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UNIVERSITY  OF  CALIFORNIA. 

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The  D.  Van  Nostrand  Company 

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EARTH  AND  ROCK 
EXCAVATION. 

A 

PRACTICAL    TREATISE. 

BY 

CHAELES  PEELINI,    C.E., 

Author  of  "  Tunneling." 
WITH  TABLES  AND  MANY  DIAGRAMS  AND  ENGRAVINGS. 

SECOND   EDITION,   REVISED. 


OF  THE 

{    UNIVERSITY  } 

OF 


NEW    YORK: 

D.   VAN    NOSTEAND    COMPANY, 

23  MURRAY  AT*D  27  WARRED  STREETS. 
LONDON  : 

CEOSBY     LOCKWOOD     &     SON, 

7  STATIONERS'  HALL  COURT,  LUDGATE  HILL. 

1906 


7 


Copyright,  1905, 

BY 

D.  VAN  NOSTRAND  COMPANY. 


ROBERT  DRUMMOND,  PRINTER,   NEW    STORK. 


P7 


PREFACE. 


THERE  is  hardly  a  class  of  engineering  construction  into  which 
excavation  of  earth  or  rock  does  not  enter  to  some  extent,  and  in 
many  engineering  works  excavation  is  by  far  the  largest  item 
of  labor  and  expense.  Despite  these  facts  English  engineering 
literature  is  almost  barren  of  books  which  treat  of  earth  and 
rock  excavation  in  a  concise  and  comprehensive  manner  having 
regard  both  for  the  planning  and  computation  of  such  work  and 
for  the  methods  and  machines  by  which  it  is  accomplished.  The 
present  book  is  an  attempt  to  supply  this  deficiency  and  has  been 
written  with  the  following  objects  chiefly  in  view:  First  to  con- 
centrate in  a  small  volume  descriptions  of  the  different  operations 
which  are  required  for  planning  and  executing  any  work  of  exca- 
vation in  either  earth  or  rock;  second,  to  classify  and  describe 
clearly  the  various  implements  and  machines  used  for  excavating 
and  hauling  away  the  material.  So  far  as  the  author  knows,  there 
is  no  book  in  the  English  language  which  covers  these  fields. 

The  contents  of  the  book,  briefly  summarized,  comprise  first 
a  discussion  of  the  graphical  repr  sentation  and  calculation  of 
earthwork.  This  section  is  followed  by  chapters  describing  the 
construction  and  operation  of  the  various  machines  used  for 
excavating  and  transporting  earth  and  rock.  Succeeding  chapters 
consider  the  various  methods  of  planning  and  executing  works  of 
excavation,  and  describe  methods  for  deducing  the  cost  of  such 
work  in  any  particular  case.  A  concluding  section  describes  briefly 
a  number  of  large  works  of  excavation.  For  his  information 


17711 


IV  PREFACE. 

regarding  the  various  excavating  machines  the  author  is  indebted 
to  the  manufacturers  and  to  the  engineering  periodicals  and 
society  transactions.  He  has  also  consulted  the  various  foreign 
works  on  excavation,  and  wherever  foreign  practice  has  seemed 
to  offer  suggestions  of  value  to  American  engineers  they  have 
been  taken.  While  the  book  is  designed  primarily  for  the  student 
and  young  engineer,  it  contains  much  information  that  is  valuable 
to  the  practicing  engineer  and  contractor  and  which  is  not  to 
be  found  elsewhere  in  one  place  convenient  for  consultation  and 
use. 

So  far  as  was  possible  the  author  has  given  credit  in  the  pages 
of  the  book  to  those  who  have  aided  him  with  advice  and  informa- 
tion. It  is  with  a  feeling  of  sincere  gratitude  that  the  author 
acknowledges  the  kindness  of  the  different  manufacturers  who 
furnished  him  with  the  details  of  the  methods  and  machines  which 
are  described  herein,  and  he  wishes  to  extend  hearty  thanks  to  all 
who  have  aided  him  in  any  way  in  the  work. 

CHARLES  PRELINI. 


•J* 

CONTENTS. 


CHAPTER  I. 

PAGE 

THE    GRAPHICAL    REPRESENTATION    OF   EARTHWORK;     PLANS   AND    PRO- 
FILES        1 

CHAPTER  II. 
METHODS  OF  CALCULATING  QUANTITIES  AND  COST  OF  EARTHWORK 9 

CHAPTER  III. 
CUTS  AND  FILLS;    BORROW-PITS  AND  SPOIL-BANKS 30 

CHAPTER  IV. 
CLASSIFICATION  OF  MATERIALS;    ROCK  EXCAVATION  WITHOUT  BLASTING.  .     42 

CHAPTER  V. 
EXCAVATION  OF  ROCK  BY  BLASTING  :   THE  DRILLING  OF  THE  HOLES 52 

CHAPTER  VI. 

ROCK  EXCAVATION  BY  BLASTING;    EXPLOSIVES  AND  THEIR  TRANSPORTA- 
TION AND  STORAGE 67 

CHAPTER  VII. 

ROCK  EXCAVATION  BY  BLASTING;    FUSES,  FIRING,  AND  BLASTING 77 

CHAPTER  VIII. 
EARTH  EXCAVATION:    HAND-TOOLS;    MACHINE  EXCAVATION 88 

CHAPTER  IX. 
EARTH  EXCAVATION:    CONTINUOUS  DIGGING-MACHINES 105 

CHAPTER  X. 

EARTH  EXCAVATION:    INTERMITTENT  DIGGING-MACHINES 118 

v 


VI  CONTENTS. 

CHAPTER  XI. 

PAGE 

METHODS  OF  HAULING  EXCAVATED  MATERIAL  ON  LEVEL  ROADS 133 

CHAPTER  XII. 
HAULING  EXCAVATED  MATERIALS  ON  HORIZONTAL  ROADS 155 

CHAPTER  XIII. 
METHODS  OF  HAULING  EXCAVATED  MATERIALS  ON  INCLINED  ROADS 172 

CHAPTER  XIV. 
VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS .    186 

CHAPTER  XV. 
TRANSPORTING  EXCAVATED  MATERIALS  BY  AERIALWAYS 206 

CHAPTER  XVI. 
TRANSPORTING  EXCAVATED  MATERIALS  BY  CABLEWAYS 220 

CHAPTER  XVII. 
TRANSPORTING  EXCAVATED  MATERIALS  BY  TELPHERAGE 243 

CHAPTER  XVIII. 
CHAINS,  ROPES,  BUCKETS,  ENGINES,  ANP  MOTIVE  POWER 256 

CHAPTER  XIX. 
ANIMAL  AND  MECHANICAL  LABOR 274 

CHAPTER  XX. 
THE  DIRECTION  OF  EXCAVATION  WORK 287 

CHAPTER  XXI. 
THE  DIRECTION  OF  EXCAVATION  WORK  (Continued} 307 

CHAPTER  XXII. 
SHRINKAGE  OF  EARTH;    COST  OF  EARTHWORK 328 

CHAPTER  XXIII. 
EXAMPLES  OF  LARGE  CANAL  EXCAVATION  WORKS .  340 


EARTH  AND  ROCK  EXCAVATION. 


CHAPTER  I. 

THE    GRAPHICAL    REPRESENTATION    OF    EARTHWORK; 
PLANS  AND  PROFILES. 

THE  first  operation  required  when  any  engineering  work  is 
undertaken  is  the  preparation  of  plans  representing  accurately 
the  labor  to  be  performed;  such  plans  are  absolutely  essential 
in  estimating  the  cost  of  the  work.  In  prosecuting  earthwork 
accurate  and  legible  plans  are  particularly  necessary.  Earthwork 
comprises  two  operations — the  cutting  down  of  the  elevations 
projecting  above  the  level  of  the  proposed  surface,  and  the  filling 
up  of  the  hollows  lying  below  the  proposed  surface.  These  oper- 
ations are  known  as  cutting  and  filling,  and  the  works  themselves 
are  called  cuts  and  fills.  The  preparation  of  plans  for  earthwork, 
therefore,  consists  in  representing  graphically  on  paper  the  depths 
and  locations  of  the  cuts  and  fills. 

To  represent  graphically  the  cuts  and  fills  of  earthwork  it  is 
usual  either  to  refer  the  proposed  surface  to  the  original  ground- 
surface,  or  else  to  refer  both  the  original  and  the  proposed  surfaces 
to  an  imaginary  horizontal  plane  located  below  the  lowest  point 
of  either.  This  is  called  the  datum  plane  and  is  used  in  all  the 
leveling  operations  connected  with  the  work.  Three  forms  of 
representation  are  employed :  the  first  is  known  as  the  method  of 
marked  points;  the  second,  as  the  method  of  contour-lines;  and 
the  third,  as  the  method  of  profile  and  cross-sections.  Generally 
the  method  of  marked  points  and  that  of  contour-lines  are  em- 


2  EARTH    AND    ROCK   EXCAVATION. 

ployed  where  the  work  occupies  an  area  of  considerable  width  as 
compared  to  its  length,  and  the  method  of  profile  and  cross- 
sections  where  the  work  occupies  an  area  which  is  narrow  as 
compared  to  its  length.  Whichever  method  is  employed,  the 
plan  must  be  so  legible  that  it  will  be  easily  understood  by  the 
constructor,  his  superintendent,  or  even  by  the  foremen  on  the 
work.  These  persons  are  presupposed  to  be  able  to  read  such 
plans  and  comprehend  their  stipulations  and  directions. 

Method  of  Marked  Points. — To  represent  earthwork  by  means 
of  marked  points  a  map  or  plan  of  the  original  ground-surface 
occupied  by  it  is  first  prepared.  On  this  map  a  greater  or  less 
number  of  fixed  points  are  marked.  These  points  may  be  either 
the  salient  points  formed  by  the  natural  surface,  or  they  may  be 
artificial  points  located  by  transit  and  marked  by  stakes.  Each 
point  is  inscribed  with  a  numeral  showing  its  vertical  distance 
from  the  proposed  surface  of  the  earthwork,  this  numeral  being 
preceded  by  a  minus  sign  if  the  distance  is  above  the  proposed 
surface,  and  by  a  plus  sign  if  the  distance  is  below  that  surface. 
Thus  the  mark  +5  will  mean  that  the  original  surface  is  to  be 
raised  5  ft.  by  filling,  and  the  mark  -5  that  the  original  surface 
is  to  be  lowered  5  ft.  by  cutting. 

An  alternative  form  for  representing  earthwork  by  means  of 
marked  points  is  as  follows:  A  datum  plane  is  chosen  and 
each  fixed  point  is  marked  by  two  numerals,  one  in  black  ink 
showing  the  altitude  of  the  original  ground-surface  above  the 
datum  plane,  and  one  in  black  ink  underlined,  or,  preferably, 
in  red  ink,  showing  the  altitude  of  the  proposed  surface  above 
that  plane.  In  this  double  notation  a  cut  is  indicated  if  the 
underlined  or  red-ink  numeral  is  smaller  than  the  black-ink 
numeral;  and,  on  the  contrary,  a  fill  is  indicated  when  the  under- 
lined or  red-ink  numeral  is  greater  than  the  black-ink  numeral. 
The  difference  between  the  numerals  shows  the  depths  of  cut  or 
fill  in  each  case.  Thus  if  we  have  a  point  bearing  the  numbers 
37  and  42,  we  know  that  the  original  ground-surface  is  lower 
than  the  proposed  surface  by  an  amount  equal  to  42  -  37  =  5,  and, 
therefore,  that  a  5-ft.  fill  is  required.  This  form  of  representing 


GRAPHICAL    REPRESENTATION   OF   EARTHWORK.  3 

earthwork,  although  very  simple,  is  seldom  used  in  this  country 
except  for  small  excavations »  where  great  accuracy  is  required, 
as  in  foundations  for  tall  buildings,  but  it  is  extensively  used  in 
Europe. 

Method  of  Contour-lines.  —  Contour-lines  are  lines  joining 
points  of  equal  elevation  on  the  ground-surface.  They  may  be 
conceived  as  being  formed  by  horizontal  planes  placed  at  regular 
vertical  intervals  apart  and  intersecting  the  ground-surface;  the 
line  where  each  plane  cuts  the  ground-surface  is  the  contour- 
line  at  that  elevation  or  level.  These  planes  of  uniform  level  are 
usually  taken  at  elevations  5  ft.  or  10  ft.  apart,  but  may  be  taken 
at  much  closer  intervals,  and  the  contour-lines  formed  by  them 
show  definitely  the  conformation  of  the  ground.  If  we,  there- 
fore, plot  on  a  plan  of  the  site  of  the  proposed  earthworks  first 
the  contour-lines  of  the  original  ground-surface  and  second  those 
of  the  surface  of  the  proposed  work,  we  have  then  clearly  indi- 
cated the  location  and  depths  of  the  required  cuts  and  fills.  For 
example,  if  a  line  of  the  first  series  at  the  20-ft.  level  is  crossed  by 
the  22-ft. -level  line  of  the  second  series,  it  indicates  that  at  the 
point  of  intersection  the  original  surface  must  be  raised  2  ft.  to 
obtain  the  proposed  surface,  or,  in  other  words,  that  a  2-ft.  fill 
is  necessary.  On  the  contrary,  if  the  20-ft.  line  of  the  first  series 
is  crossed  by  the  18-ft.  line  of  the  second  series,  it  indicates  that 
a  2-ft.  cut  is  required.  In  plotting  these  two  sets  of  contour-lines 
on  the  plan  the  set  referring  to  the  proposed  surface  of  the  work 
is  usually  distinguished  by  being  drawn  in  colored  ink;  usually 
red  ink  is  used.  The  contour-line  method  of  representing  earth- 
work is  employed  particularly  for  works  like  reservoirs,  drainage, 
irrigation,  and  the  improvement  of  submerged  or  tidal  lands. 
Such  a  plan  is  of  great  use  in  locating  and  making  rough  estimates 
of  the  cost  of  canals,  roads,  and  railways;  but  in  this  country  it 
is  seldom  employed  for  the  accurate  location  and  calculation  of 
such  works. 

Method  of  Profile  and  Cross-sections.  —  The  most  commonly 
employed  method  of  representing  earthworks  is  by  a  longitudinal 
profile  and  cross-sections.  This  method  is  particularly  con- 


4  EARTH    AND    ROCK    EXCAVATION. 

venient  for  representing  works  which  are  of  small  width  and 
great  length,  such  as  roads,  canals,  and  railways.  The  fixing 
of  the  axes  of  these  works  is  a  separate  task,  and  it  will  not  be 
discussed  in  this  book  except  to  note  that  it  should  be  the  result 
of  a  careful  study  of  the  technical,  economical,  and  other  con- 
ditions of  the  route.  The  axis  of  the  work  when  once  decided 
upon  is  marked  on  the  ground  with  stakes  spaced  100  ft.  apart 
and  numbered  progressively  from  the  starting  bench-mark  or 
monument.  The  longitudinal  profile  is  the  line  formed  by  the 
intersection  of  a  vertical  plane  through  the  axis  with  the  sur- 
face of  the  ground.  Cross-sections  are  formed  by  vertical  planes 
at  right  angles  to  the  axis  and  are  usually  taken  100  ft.  apart 
or  at  every  stake  marking  the  axis.  The  profile  and  cross- 
sections  together  give  when  plotted  on  paper  a  clear  graphical 
representation  of  the  configuration  of  the  ground.  The  deter- 
mination of  the  profile  and  cross-sections  is  usually  accomplished 
by  the  ordinary  engineer's  level,  but  on  side-hill  work  or  where 
obstacles  are  frequent  the  cross-section  rod  gives  better  results. 
The  longitudinal  profile  is  plotted  on  profile  paper  which  is  es- 
pecially printed  for  this  purpose,  and  two  different  scales  are  used, 
one  for  the  horizontal  distances,  which  is  usually  400  ft.  to  1  in., 
and  another  for  the  vertical  distances,  which  is  usually  30  ft. 
to  1  in.  The  larger  vertical  scale  gives  a  distorted  profile,  but 
one  in  which  every  irregularity  of  the  surface  is  magnified,  and 
this  is  its  purpose.  The  grade-line  of  the  proposed  work  is  plotted 
on  this  profile  at  its  proper  elevation;  all  portions  of  the  profile 
which  come  above  this  grade-line  constitute  cuts,  and  all  portions 
which  come  below  constitute  fills.  The  points  where  the  grade- 
line  intersects  the  profile  are  called  points  at  grade,  and  they 
are  marked  on  the  ground  by  stakes. 

European  engineers  in  plotting  the  profile  adopt  a  some- 
what different  practice  than  that  just  described.  Instead  of  set- 
ting the  stakes  marking  the  axis  always  100  ft.  apart,  they  set 
them  wherever  a  change  in  direction  occurs  on  the  ground-sur- 
face. Thus,  for  instance,  if  the  ground-surface  is  substantially 
unbroken  the  stakes  may  be  set  as  much  as  300  ft.  apart,  but 


PLANS    AND    PROFILES.  5 

if  the  surface  is  very  uneven  the  stakes  may  be  set  only  a  few 
feet  apart.  A  heavy  line  is  drawn  to  represent  the  datum  plane, 
and  parallel  to  it  four  other  fees  are  drawn,  one  being  marked 
with  the  elevations  above  datum  of  the  ground-surface,  another 
with  the  elevations  above  datum  of  the  proposed  work,  and  the 
third  and  fourth  with  the  partial  and  the  progressive  datums  of 
the  various  stakes  or  stations.  As  in  American  practice,  hori- 
zontal distances  and  vertical  elevations  are  drawn  to  different 
scales.  Fig.  1  represents  a  profile  drawn  according  to  American 
practice,  and  Fig.  2  represents  the  same  profile  drawn  according 
to  European  practice,  in  which  all  elevations,  distances,  grades, 
depths  of  cuts  and  fills,  etc.,  are  enumerated  on  the  drawing. 
The  longitudinal  profile  is  generally  supplemented  by  a  plan 
which  shows  the  developed  grade-line  of  the  proposed  work. 

The  longitudinal  profile  alone  does  not  completely  show 
the  configuration  of  the  ground,  and  it  is,  therefore,  supplemented 
by  cross-sections  which  are  in  effect  transverse  profiles  taken  at 
•chosen  intervals  and  at  right  angles  to  the  plane  of  the  longi- 
tudinal profile.  These  cross-sections  are  determined  by  either 
an  engineer's  level  or  by  a  cross-section  rod.  They  are  plotted 
to  a  scale  equal  to  the  vertical  scale  of  the  profile,  sometimes 
on  the  profile  sheet,  but  more  often  on  separate  sheets.  Each 
cross-section  bears  a  number  corresponding  to  the  number  on 
the  profile  which  marks  the  point  where  the  section  was  taken. 
Usually  the  cross-section  is  taken  for  a  distance  each  side  of  the 
axis  which  is  somewhat  greater  than  that  marking  the  outer 
limits  of  the  projected  work.  A  common  practice  is  to  cross- 
section  a  width  three  times  as  great  as  the  width  of  the  work. 
The  purpose  of  this  is  to  include  the  slopes  of  the  cuts  and  fills 
and  to  permit  if  desired  the  axis  to  be  shifted  to  one  side  or  the 
other  without  the  necessity  of  determining  and  plotting  new 
cross-sections. 

In  plotting  cross-sections  the  original  ground-surface  is  denoted 
by  a  full  black  line  and  the  surface  of  the  proposed  construction 
is  denoted  by  a  full  line  in  red  ink  or  a  broken  line  in  black  ink. 
Fig.  3  is  an  example  of  a  cross-section  plotted  in  black  ink.  Here 


6 


EARTH    AND    ROCK   EXCAVATION. 


PLANS   AND    PROFILES. 


the  line  ABCD  represents  the  original  ground-surface,  and  the 
line  AEFGHD  the  surface  of  the  proposed  work.  A,  K,  and  D 
are  points  at  grade.  The  triangle  AEK  shows  a  fill,  and  the 


FIG.  3. 

irregular  figure  KBCDHGF  shows  a  cut.  It  is  common  practice 
in  both  the  profile  and  the  cross-sections  either  to  enter  the  fills 
and  cuts  differently,  or  to  use  section-lining  and  stippling  to  dis- 
tinguish them.  The  cross-sections  are  usually  marked  also  with 
all  dimensions,  depths  of  cut  and  fill,  slope  of  banks,  etc.  The 
total  width  of  cross-section  represents  what  French  engineers 


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FIG.  4. 

call  the  emprise,  which  is  the  strip  of  land  occupied  by  the  construc- 
tion and  whose  boundaries  it  is  very  useful  to  know  in  determining 
the  compensation  to  be  paid  the  owners. 

A  modification  of  the  method  of  profile  and  cross-sections, 
which  is  used  in  the  Public  Works  departments  of  the  city  of 
New  York,  is  illustrated  by  Fig.  4.  The  stations  are  taken  100  ft. 


8  EARTH    AND    ROCK    EXCAVATION. 

apart,  and  at  each  station  the  elevations  of  both  side  lines  and 
the  axis  of  the  ground-surface  are  determined.  These  elevations 
give  the  engineer  three  profile  lines,  one  at  each  boundary  and 
one  at  the  center  line  of  the  work,  which  are  plotted  as  shown 
by  the  illustration,  and  with  a  different-colored  ink  or  a  different 
symbol  for  each  line.  The  station-lines  extended  below  the  datum 
line  serves  as  a  basis  for  a  plot  of  the  cross-section  at  each  station. 
The  scale  used  is  usually  100  ft.  to  1  in.  horizontal  and  20  ft.  to 
1  in.  vertical,  but  this  scale  is  varied  with  the  size  of  the  work. 

The  method  of  longitudinal  profile  and  cross-sections,  while 
particularly  adapted  for  representing  long  and  narrow  earth- 
works, can  also  be  used  for  representing  earthworks  of  more 
nearly  equal  lateral  dimensions,  such  as  reservoirs  and  railway 
yards.  In  such  cases  a  series  of  cross-sections  are  taken  perpen- 
dicular to  a  chosen  base-line  and  equal  distances  apart. 


CHAPTER  II. 

METHODS  OF  CALCULATING  QUANTITIES  AND 
COST  OF  EARTHWORK. 

IN  planning  earthwork,  as  in  planning  any  other  engineering 
work,  it  is  one  of  the  first  duties  of  the  engineer  to  calculate  its 
cost.  The  cost  is  given  by  multiplying  the  total  volume  of  the 
work  by  a  figure  representing  the  estimated  cost  per  unit  of  vol- 
ume. The  first  thing  to  be  determined  in  calculating  the  cost 
of  earthwork  is,  then,  the  volume,  and  in  this  chapter  we  shall 
outline  the  various  methods  of  performing  this  task  which  are 
practiced  by  engineers. 

As  already  explained,  earthwork  is  made  up  of  cuts  and  fills; 
the  total  volume  of  any  earthwork  is,  then,  the  sum  of  its  cuts 
and  fills.  This  sum  is  determined  differently  for  works  which 
occupy  a  long  narrow  area  and  for  works  which  occupy  areas  of 
approximately  equal  lateral  dimensions.  We  shall  consider  sep- 
arately the  methods  adapted  for  each  form  of  work. 

WORKS   LONG   AND    NARROW   IN   AREA. 

When  the  work  to  be  done  occupies  a  very  long  and  compara- 
tively narrow  strip  of  land  it  is  usually  represented  by  a  longi- 
tudinal profile  and  numerous  cross-sections,  as  already  explained. 
The  total  amount  of  cut  and  fill  is  given  by  the  sum  of  the  cuts 
and  fills  between  the  consecutive  cross-sections.  There  are 
several  methods  of  determining  the  volume  of  cut  and  fill 
between  two  consecutive  cross-sections.  Some  of  these  methods 
involve  long  calculations  and  give  absolute  results,  and  others 
require  only  short,  simple  calculations,  and  give  only  approxi- 
mate results. 

9 


10  EARTH  AND  ROCK  EXCAVATION. 

Correct  Method. — Accurately  speaking,  there  is  no  absolutely 
correct  method  for  calculating  earthwork.  All  calculations 
assume  the  solid  to  be  figured  to  be  bounded  by  planes,  while 
the  actual  bounding  surfaces  are  irregular  and  undulating. 
Assuming,  however,  that  the  solid  is  bounded  by  planes  parallel 
to  the  vertical  plane  passing  through  the  axis  of  construction, 
then  the  volume  of  that  solid  is  easily  obtained.  If  a  and  b  are 
the  areas  of  the  two  consecutive  cross-sections,  and  d  is  their 
horizontal  distance  apart,  then  the  volume  of  the  solid  between 
these  cross-sections  is  represented  by 


It  is,  however,  very  seliiom  that  the  solid  is  bounded  by  planes 
parallel  to  the  axis. 

Let  ABCD  and  EFGH  (Fig.  5)  be  two  consecutive  cross-sections, 

^ P'  of  which  the  first  is  the  smaller. 

/  \  From  A  and  B  draw  planes  parallel 

to  the  axis  of  the  road;  the  larger 
cross-section  will  thus  be  divided 
into  three  parts — two  triangles  FJI 
and  LKH,  and  the  irregular  poly- 
gon IJFGLK.    The  solid  will  like- 
^5  wise  be   divided   into  three  other 
FlG  5  solids  which  are  a  large  prismoid 

included  between  the  planes  parallel 

to  the  axis  of  the  road,  and  two  triangular  pyramids  with  their 
vertices  at  A  and  B  respectively. 

Let  A  =the  area  of  the  cross-section  A  BCD; 
B=  "      "      "    "  "  EFGH; 

a=  "       "       "     "     triangle         EIJ; 
/?=  "      "      "     "          "  KLH. 

The  volume  of  the  solid  will  be, 


.«+/? 

V- = d+-- 


CALCULATING    QUANTITIES   AND    COST    OF    EARTHWORK.         11 

or 


or 


The  volume  can  also  be  obtained  by  graphics,  as  shown  by 
Fig.  5a.  On  a  horizontal  line  draw  to  any  convenient  scale  a 
segment  equal  to  d.  At  each 
extremity  of  this  segment  erect 
indefinite  perpendiculars  and  lay 
off  on  them  segments  equal  to  A 


A  and  to  B  --  ~  respectively. 

o 

r™  -11  i    •  FIG.  5a. 

These   segments  will  contain  as 

many  lineal  units  as  there  are  units  of  surface  in  the  two  areas. 
Close  the  figure  by  uniting  C  and  D,  and  the  trapezoid  ABCD 
will  contain  as  many  units  of  surface  as  there  are  units  of  volume 
included  between  the  two  cross-sections  A  and  B. 

Prismoidal  Formula.  —  Mr.  John  D.  Henck,  C.E.,  in  his  Field 
Book  for  Railroad  Engineers,  says  that  any  prismoid  can  be 
divided  into  prisms,  wedges,  and  pyramids  of  equal  altitude, 
and  its  volume  can  be  easily  obtained  from  the  sum  of  the  vol- 
umes of  the  various  solids  into  which  it  has  been  divided.  Let  b 
be  the  base  of  any  prism  and  let  a  be  its  altitude;  its  volume 
will  then  be  given  by 

v  =  aXb. 

If  b  represent  the  base  of  a  regular  wedge,  or  half  a  parallelo- 
pipedon,  and  a  represent  its  altitude,  its  volume  will  be  given  by 


If  b  represent  the  base  of  any  pyramid  with  the  altitude  a, 
its  volume  will  be 


The  combined  volumes  of  these  three  bodies  admit  of  a  common 
expression  which  may  be  found. 


12  EARTH  AND  ROCK  EXCAVATION. 

Let  m  represent  the  middle  area  of  either  of  these  solids, 
that  is,  the  area  of  a  section  parallel  to  the  base  and  midway 
between  the  base  and  top. 

For  the  prism  ra=  b. 
For  the  wedge  m  =  %b. 
For  the  pyramid  m  =  %b. 

The  upper  base  of  the  prism  is  equal  to  b  and  the  upper  bases 
of  the  wedge  and  pyramid  are  each  zero.  Then  the  expressions 
ab,  %ab,  and  ^ab,  representing  the  volumes  of  the  prism,  wedge, 
and  pyramid,  may  be  thus  transformed  : 

Solidity  of  prism 
"  wedge 

"  pyramid 

Hence  the  solidity  of  either  of  these  bodies  is  found  by  adding 
together  the  area  of  the  upper  base,  the  area  of  the  lower  base, 
and  four  times  the  middle  area,  and  multiplying  the  sum  by 
one-sixth  of  the  altitude.  Irregular  wedges,  as  those  not  half- 
parallelopipedons,  may  be  measured  by  the  same  rule,  since  they 
are  the  sum  or  difference  of  a  regular  wedge  and  a  pyramid 
of  common  altitude  ;  and  as  the  rule  applies  to  both  these  bodies, 
it  applies  to  their  sum  or  difference. 

Now,  a  prismoid,  being  made  up  of  prisms,  wedges,  and 
pyramids  of  common  altitude  with  itself,  will  have  for  its  solidity 
the  sum  of  the  solidities  of  the  combined  solids.  But  the  sum  of 
the  areas  of  the  upper  and  lower  bases  of  the  combined  solids 
is  equal  to  B  +  B',  the  sum  of  the  areas  of  the  parallel  faces  of 
the  prismoid;  and  the  sum  of  the  middle  areas  of  the  combined 
solids  is  equal  to  M,  the  middle  area  of  the  prismoid.  Therefore 


which   is   the    prismoidal   formula   commonly   employed    in   the 
calculation  of  earthwork. 


CALCULATING    QUANTITIES    AND    COST    OF    EARTHWORK.         13 

This  formula  can  also  be  graphically  represented,  since  it  can 
be  written 


Draw  an  indefinite  horizontal  line  and  lay  off  on  a  convenient 
scale  a  segment  equal  one-third  the  distance  between  the  two 
cross-sections.  At  its  extremities  erect  perpendiculars,  and  lay 
off  on  one  the  sum  B  +  B^  and  on  the  other  the  sum  4Af.  Close 
the  figure  by  uniting  C  and  D,  and  the  figure  ABCD  will  contain 
as  many  units  of  surface  as  there  are  units  of  volume  in  the  pris- 
moid  included  between  the  two  cross-sections  A  and  B.  To 
calculate  earthwork  by  either  the  correct  method  or  by  the  pris- 
moidal  formula,  although  not  abstruse,  is  a  long  and  tedious 
operation,  so  that  it  is  common  in  actual  work  to  adopt  more 
expeditious  methods. 

Mean  End  Areas.  —  The  simplest  method  of  calculating  earth- 
work is  by  averaging  the  areas  of  the  two  end  sections  and  mul- 
tiplying this  sum  by  the  distances  between  the  cross-sections.  If 
A  and  B  are  the  areas  of  the  two  cross-sections  and  d  is  their 
distance  apart,  then  the  volume  is  given  by 


The  volume  of  the  prismoid  thus  calculated  is  greater  than 
the  volume  obtained  by  the  correct  method,  the  difference  being 

—  ^,  or  half  the  volume   of  the  two  pyramids  separated  from 

the  prismoid  by  means  of  two  vertical  planes  passing  through 
the  exterior  ends  of  the  smaller  cross-section  and  parallel  to  the 
axis  of  the  prismoid.  The  error  will  decrease  the  nearer  the  ver- 
tical bounding  planes  are  to  being  parallel  with  the  axial  plane, 
and  it  will  increase  the  more  the  bounding  planes  diverge  from 
a  parallel  to  the  axial  plane. 

The  calculation  of  the  volume   of  earthwork,   by  averaging 
the  end  areas  of  the  two  cross-sections,  is  performed  in  two  differ- 


14 


EARTH    AND    ROCK    EXCAVATION. 


ent  ways,  either  by  measuring  directly  the  quantities  of  cuts  and 
fills  included  within  the  solid,  or  indirectly  by  taking  the  average 
of  the  quantities  of  cuts  and  fills  in  the  two  end  areas  and  multi- 
plying it  by  their  distance  apart. 

Direct  Method.  —  The  direct  method  is  more  correct,  although 
it  is  more  complicate,  and  all  the  different  cases  which  may  be 
encountered  will  be  considered. 

1st  Case.  Both  Cross-sections  in  Cut  or  Both  in  Fill.  —  This 
case  has  already  been  considered,  and  the  volume  is  given  by 


This  manner  of  measuring  the  volume  can  be  compared  with  the 
area  of  a  trapezium,  ABCD,  in  which  the  parallel  sides  and  the 
altitude  are  respectively  proportional  to  the  areas  of  the  two  cross- 
sections  and  their  distance  (Fig.  6).  The  trapezium  will  contain 
c 


FIG.  6. 

as  many  units  of  surface  as  there  are  units  of  volume  in  the  solid. 
2d  Case.  One    section,    A,    in    Cut  and    Cross-section,  B,   in 
Fill. — The  volume  of  the  cut  is  given  by 

A2    d 


and  that  of  the  fill  by 


A  +  B2' 


B2    d 


A+B2' 


These  volumes  are  clearly  indicated  by  graphics  (Fig.  7).  On 
the  horizontal  line  AB  take  a  segment  equal  d;  at  its  extremities 
erect  perpendiculars  in  opposite  directions.  On  one  lay  off  a 


CALCULATING    QUANTITIES   AND    COST    OF    EARTHWORK.         15 


segment  equal  to  A,  representing  the  cut;  and  make  the  other 
perpendicular  equal  to  the  fill  B;  unite  C  with  D.  The  point  0 
will  be  the  point  at  grade.  Trie  units  of  surface  in  the  triangle 
OAC  will  represent  the  units  of  Volume  of  the  cut,  while  those  of 
c 


FIG.  7. 

the  triangle  OBD  will  represent  the  volume  of  fill.    The  quantities 

A  B 

of  the  cuts  will  be  given  by  -^AO,  and  those  of  the  fills  by  -^-BO. 

From  the  similar  triangles  AOC  and  BOD  we  have 


but 
therefore 


A:B=AO:OB; 
OB=AB-OA, 

A:B  =  AO:AB-OA 
BXAO=AXAB-AXOA 
BXAO+AXOA=AXAB 
=AXAB 
AXAB 


A0  = 


A  +  B 


AB  being  equal  to  d  and  the  quantity  of  cut  being  given  by  — AO, 
then 


Ad 


A2    d 


2^A  +  B    A+B2 


16 


EARTH   AND    ROCK    EXCAVATION. 


752         J 

In  a  similar  way  it  is  found  that  the  fill  B  is  equal  to  -: — ^  -. 

A.  -\-  ij  2i 

3d  Case.  One  Cross-section  in  Cut  or  Fill,  and  the  other  Cross- 
section  Part  in  Cut  and  Part  in  Fill  (Fig.  8). — The  second  section 


M^P:'^Sk>;: 
>S^1^®ffiS-£ 


FIG.  8. 

being  part  in  cut  and  part  in  fill,  the  line  of  the  project  will  inter- 
sect the  ground-surface  at  the  point  0,  thus  dividing  this  cross- 
section  into  the  parts  B  and  Blf  the  former  in  fill  and  the  latter 
in  cut.  Imagine  a  vertical  plane  passing  through  0  and  parallel 
to  the  axis  of  the  construction;  this  will  divide  the  first  cross- 
section  into  two  parts,  A  and  A',  both  in  fill.  The  volume  of  the 
fill  at  the  left  of  this  vertical  plane  is  given,  according  to  the  1st 


case, 


A+A, 


I,  and  the  volumes  at  the  right-hand  side  of  the 


same  vertical  plane  are  given,  according  to  the  2d  case,  by 


cut 


^-     and 


fill 


B2    d 


B  +  B'2' 


CALCULATING   QUANTITIES   AND   COST   OF   EARTHWORK.  17 


So  that  the  total  volume  of  the  solid  will  be 

B2    d 


Cut  = 


B?    d 


B+B.2' 

4th  Case.  Both  Cross-sections  are  Part  in  Cut  and  Part  in 
Fill,  and  the  Points  at  Grade  Correspond  with  the  Axis  of  the 
Construction  (Fig.  9). — The  volumes  of  the  cuts  and  fills  are  cal- 


FIG.  9. 

culated  as  in  the  first  case.  If  a  vertical  plane  is  supposed  to 
pass  through  the  axis  of  the  construction,  we  have  at  the  left  hand 
two  cross-sections,  A  and  B,  both  in  fill,  and  the  volume  will  be 

A-\-B 
given  by  — 9— d;    at  the  right-hand  side  of    the  vertical  plane 

there  are  two  sections,  Al  and  Blt  both  in  cut,  and  the  volume  will 

be  given  by  — ^ — ld.  Between  these  two  cross-sections  we 
shall  have 


Cut=^±^d     and    Fill=^pd. 

2  - 


18 


EARTH    AND    ROCK   EXCAVATION. 


5th  Case.  Both  €ross-sections  are  Part  in  Cut  and  Part  in 
Fill,  but  the  Points  at  Grade  are  not  Along  the  Same  Vertical 
Plane. — From  the  points  at  grade  0  and  Olt  Fig.  10,  draw  two 


FIG.  10. 

vertical  planes  parallel  to  the  axis  of  the  construction.  These 
planes  will  divide  the  two  cross-sections  into  three  parts,  A^A^Ajf 
and  B,  BT,  Bu,  respectively.  The  volume  of  the  solid  contained 
between  these  two  cross-sections  is  the  sum  of  the  cuts  and  fills 
of  these  new  solids  into  which  the  former  solid  was  divided;  and 
they  are  limited  by  A  and  B,  Aj  and  BIy  An  and  Bn.  A  and  B 

being  both  in  fill,  the  volume  is  given  by  —  o~~d-  ^ne  sec^ons 
Ax  being  in  cut  and  B2  in  fill,  the  volume  of  the  cut  is  given  by 


1 


that  of  the  fill  by 


^r.     The  sections  A    and 


A  +Z? 
Bn  being  both  in  cut,  the  volume  is  given  by  — ~ — -  d.    The 


CALCULATING    QUANTITIES   AND    COST    OF    EARTHWORK.         19 

total  volume  of  the  solid  included  between  the  two  cross-sections 
will  be  :..•* 


Indirect  Method.  —  It  is  easier,  although  less  accurate,  to 
calculate  the  volumes  of  the  earthwork  by  the  mean  end-area 
method  in  an  indirect  way,  and  this  is  done  by  the  simple  con- 
struction of  tables  in  which  are  recorded  all  the  data  and  calcu- 
lations. The  following  table,  taken  from  Lenti,  gives  the  method 
employed  by  the  Italian  government  engineers  for  calculating  the 
volumes  of  earthwork.  This  is  obtained  by  marking  separately 
the  area  of  the  cuts  and  fills  on  each  cross-section,  and  then  taking 
the  average  of  the  areas  of  cuts  and  fills  between  two  consecutive 
cross-sections.  These  averaged  areas  are  multiplied  by  the  dis- 
tance of  the  cross-section  apart,  and  thus  the  volumes  of  the 
cuts  and  fills  are  obtained. 

The  table  for  the  calculation  of  the  earthwork  contains  only 
eight  columns,  but  a  few  others  are  added  in  order  to  keep  record 
and  for  calculating  also  the  amount  of  the  different  kinds  of  soil 
encountered  in  the  excavation.  In  the  first  column  are  recorded 
the  various  cross-sections  progressively;  in  columns  2  and  3  are 
marked  the  area  of  the  cut  or  fill  in  the  corresponding  cross- 
section;  in  columns  4  and  5  are  marked  the  averaged  areas  of 
the  cuts  and  fills  between  the  two  consecutive  cross-sections;  in 
column  6  are  recorded  the  distances  between  the  two  consecutive 
cross-sections,  and  in  columns  7  and  8  are  given  the  volumes  of 
the  cuts  and  fills,  or  the  products  of  columns  4  and  6,  and  5  and 
6,  respectively.  The  sum  of  columns  7  and  8  will  give  the  total 
amount  of  cuts  and  fills  required  for  the  construction  of  the  road, 
as  indicated  by  the  longitudinal  profile  and  cross-section.  In 
columns  9,  10,  and  11  are  recorded  the  amount  of  earth  of  the  cuts, 
classified  according  to  their  resistance.  If  they  are  of  vegetable 
ground  or  loose  soil,  in  column  9;  resistant  and  compact  soils,  as 


20 


EARTH    AND    ROCK    EXCAVATION. 


clay  and  gravel,  in  column  10;  and  in  column  11  the  rock.  An- 
other column  is  usually  added  in  which  are  recorded  all  the  obser- 
vations relating  to  the  work.  It  is,  however,  to  be  remembered 
that  in  the  first  column,  as,  for  instance,  between  sections  3  and 
4,  5  and  6,  and  7  and  8,  there  are  supplementary  cross-sections 
marked  P.G.;  this  means  points  at  grade,  and  they  should  always 
be  recorded.  These  points  at  grade  are  given  by  writing  in 
columns  2  and  3  the  same  values  of  F.  or  C.  that  are  marked  in 
columns  2  and  3  in  the  consecutive  cross-section  or  the  successive 
one. 

TABLE  I. 


Pro- 
gres- 

Surface of 
Sections. 

Averaged 
Surfaces. 

Dis- 
tance 

Volumes. 

Nature  of  the  Soil. 

sive 

between 

Num- 

thf» 

Oh«Ar 

ber 

tne 
Succes- 

vjDser— 
vations. 

of  the 
Cross- 

Fill- 

Cuts. 

Fill- 

Cuts. 

sive 
Cross- 

Fill- 

Cuts. 

Loose 

Per- 
sistent 

Rock. 

sec- 

ings. 

ings. 

sections. 

ings. 

Soil. 

Soil. 

tions. 

1 

0.00 

0.00 

0.56 

1.81 

30 

16.80 

54.30 

34.30 

20 

2 

1.12 

3.62 

0.81 

4.54 

18.80 

15.22 

85.35 

55.35 

30 

3 

0.50 

5.45 

P.O. 

0.50 

5.45 

0.25 

1 

12.02 

3.00 

8.87 

29.60 

3.00 

262.55 

162.55 

100 

4 

0.00 

12.28 

14.25 

14.30 

203.51 

103.51 

100 

5 

0.00 

16.22 

0.25 

14.25 

4.35 

1.09 

P.G. 

0.49 

16.22 

13.41 

15.00 

201.15 

101.15 

100 

6 

0.49 

10.61 

2.40 

8.69 

15.00 

36.00 

130.35 

80.35 

50 

7 

4.31 

6.76 

2.40 

6.93 

14.80 

102.56 

P.G. 

0.00 

6.76 

20 

3.38 

12.07 

102.56 

40.80 

21.80 

1900 

8 

9.54 

0.00 

15.78 

13.70 

216.19 

9 

22.01 

0.00 

15.78 

French  engineers  use  another  method  for  calculating  the 
total  amount  of  cuts  and  fills  in  earthwork  excavations.  They 
do  not  take  the  average  of  the  two  consecutive  cross-sections  as 


CALCULATING    QUANTITIES    AND    COST    OF    EARTHWORK.         21 


the  Italian  engineers  do,  but  they  calculate  directly  the  solids 
contained  between  the  two  cross-sections  as  having  a  constant 
base  and  equal  to  the  second  ^pf  the  cross-sections  considered. 
Besides,  on  each  cross-section  they  calculate  separately  the  por- 
tions at  the  right  and  left  of  the  axis  of  the  construction  and 
make  up  a  table  of  ten  columns,  with  an  additional  one  for  the 
observations  regarding  the  work.  The  sums  of  columns  6  and 
10  give  the  total  amount  of  the  cuts  and  fills,  respectively,  required 
for  the  work.  The  following  table,  illustrating  this  method,  is 
taken  from  Daries. 

TABLE  II. 


Num- 
ber of 
Cross- 
section. 

1 

Dis- 
tance. 

2 

Cuts. 

Fillings. 

Obser- 
vations. 

11 

Right. 
3 

Left. 
4 

Total. 
5 

Vol- 
umes. 
6 

Right. 

,     7 

Left. 

8 

Total. 
9 

Vol- 
umes. 
10 

1 

P.G. 

2 
3 
4 
5 
6 
P.G 
7 
8 
9 
10 

21.47 
30.50 
42.53 
56.50 
50 
39.50 
36.62 
43.50 
53.88 
45.00 
2S.OO 
17.50 

15.50 
12.07 

8.53 
13.19 
0.37 
0.15 

9.97 
2.24 

10.32 
29.91 
5.0? 
5.93 

25.47 
14.31 

18.85 
43.10 
5.45 
6.13 

547 

716 

1016 
1940 
153 
107 

2.03 
12.20 

8.68 
22.25 

1.87 
20.49 
10.90 

10.71 
34.35 
1.87 
40.61 
23.45 

455 
1946 
94 
1604 
859 

20.12 
12.55 

0.54 
4.16 

0.54 
4.16 

15 
73 

465 

5046 

4479 

All  the  numbers  are  in  meters,  and  consequently  for  a  distance  of  465 
meters  will  be  5046  cubic  meters  of  cuts  and  4479  cubic  meters  of  fillings. 

Profile  of  Masses, — From  the  end-area  method  used  in  the 
calculation  of  earthwork  can  be  easily  constructed  the  profile  of 
the  masses,  which  is  the  graphical  representation  of  all  the  cuts 
and  fills  required  for  the  work.  Besides,  it  will  give  a  correct 
idea  in  what  direction,  either  longitudinally  or  transversally  to 
the  axis  of  the  construction,  the  earth  should  be  moved  from 
their  present  position  in  order  to  reduce  the  ground  in  the  manner 
indicated  in  the  project. 


22  EARTH  AND  ROCK  EXCAVATION. 

Considering,  for  instance,  the  cross-sections  whose  dimensions 
and  calculation  of  the  earthwork  are  given  in  Table  I,  the 
profile  of  the  masses  is  drawn  in  the  following  manner.  A  hori- 
zontal line,  XY,  represents  the  longitudinal  axis  of  the  construction, 
and  along  this  are  marked  points  representing  the  distances  of 
the  various  cross-sections  from  the  origin.  The  origin  in  our  case 
will  be  at  the  cross-section  1,  and  it  must  be  taken  a  distance 
along  XY  equal  to  30,  so  as  to  have  the  point  of  the  cross-section 
No.  2,  and  then  another  segment  equal  18.80  will  indicate  the 
point  of  the  section  3,  and  12.02  indicate  the  point  at  grade,  and 
again  the  distance  of  29.60  from  this  will  give  the  location  of  the 
cross-section  4,  and  so  on.  In  a  word,  along  the  horizontal  line 
XY  are  laid  off  segments  representing  in  scale  the  distances  apart 
of  the  various  cross-sections.  At  these  points  are  erected  per- 
pendicular lines,  and  on  these  are  laid  off  segments  representing 
the  area  of  the  various  cross-sections.  The  segments  representing 
the  cuts  are  laid  off  above  the  horizontal  line,  and  those  repre- 
senting the  fills  are  laid  off  below.  The  scale  used  to  represent 
the  areas  is  usually  different  and  much  larger  than  the  one  em- 
ployed for  the  distances.  Station  1,  in  which  there  are  neither 
cuts  nor  fills,  as  indicated  in  the  table,  is  the  origin.  Then  along 
the  perpendicular  erected  at  the  station  2  above  is  laid  off  a 
segment  equal  to  3.62,  representing  the  cut,  and  below  another 
equal  to  1.12,  representing  the  fill.  On  section  3  above  there  is 
a  cut  of  5.46,  and  below  a  fill  equal  to  0.50;  then  at  the  point 
P.O.,  which  is  distant  12.02  from  station  3,  there  are  no  more 
fills  and  all  the  sections  are  in  cuts.  Thus  there  is  found  on 
section  4  a  cut  of  12.28,  and  16.22  at  the  station  5.  At  a  point 
1.35  from  station  5  there  is  the  point  at  grade  P.G.,  because  the 
fills  begin  again,  and  it  is  found  to  be  0.49  at  station  6,  while  the 
cut  is  10.61.  At  station  7  the  cut  is  6.76  and  the  fill  4.31,  and  the 
cuts  come  to  0  at  the  P.O.  14.8  from  station  7.  Then  stations  8 
and  9  are  all  in  fills,  and  segments  equal  to  9.54  and  22.01,  re- 
spectively, are  laid  off.  Connecting  all  the  points  above  the  hori- 
zontal line  XY,  an  irregular  figure  is  obtained  which  will  contain 
as  many  units  of  surface  as  there  are  units  of  volume  hi  the  cuts 


CALCULATING    QUANTITIES    AND    COST    OF    EARTHWORK.         23 

to  be  made;  while  the  irregular  figure  below  the  line  XY  will 
have  as  many  units  of  surface?  as  there  are  units  of  volume  in 
the  fills  to  be  made,  so  as  to  jeduce  the  present  ground -surf  ace 
as  required  by  the  project. 

This  diagram,  given  in  Fig.  11,  gives  a  clear  idea  of  the  direc- 


FIG.  11. 

tion  of  the  movements  of  the  masses  of  earth,  the  portions  that 
are  compensated  on  the  same  cross-section,  and  those  which 
have  to  be  transferred  along  the  longitudinal  axis  of  the  road. 
It  is  the  real  graphical  representation  of  the  cuts  and  fills  which 
is  required  for  the  construction  of  the  work  between  the  two 
limiting  cross-sections  1  and  9. 

Rough  Calculation  Deduced  from  the  Longitudinal  Profile. — 
In  some  particular  cases  a  rough  calculation  of  the  earth- 
work can  be  obtained  in  a  very  simple  way  by  being  directly 
deduced  from  the  longitudinal  profile  of  the  axis  of  the  construc- 
tion. The  tedious  work  of  calculating  all  the  volume  of  the 
prisms  included  within  the  various  cross-sections  is  in  this  manner 
dispensed  with.  But  this  method  is  possible  only  when  the 
surface  of  the  project  is  parallel  to  the  ground-surface.  It  con- 
sists in  calculating  the  volumes  of  the  cuts  and  fills  for  the 
various  portions  of  the  road.  For  each  portion  which  is  either 
in  cut  or  in  fill  calculate  a  standard  cross-section  whose  dimen- 


24  EARTH  AND  ROCK  EXCAVATION. 

sions  are  the  average  dimensions  of  the  various  cross-sections 
of  this  portion  of  the  road.  Such  an  average  area  multiplied 
by  the  total  length  of  the  considered  portion  will  give  the  volume 
of  cut  or  fill  for  that  portion  of  the  road.  Repeating  the  same 
operation  for  each  of  the  various  portions  into  which  the  road 
has  been  divided,  the  total  volume  of  the  cuts  and  the  fills  required 
for  the  work  can  be  easily  deduced.  It  is  obvious  that  such 
a  manner  of  calculating  the  volumes  of  the  cuts  and  fills  would 
be  entirely  wrong  in  cases  where  the  cross-sections  were  part 
in  cut  and  part  in  fill,  and  in  cases  in  which  the  surface  of  the  road- 
bed is  inclined  to  the  ground-surface. 

Calculation  of  Earthwork  Extending  Over  Large  Surfaces. — 
So  far  we  have  reviewed  only  the  various  methods  of  calculating 
earthworks  in  works  greatly  extending  in  length  while  the  width 
of  the  construction  was  very  narrow.  But  there  are  cases  in 
which  the  work  extends  in  width  as  well  as  in  length,  and  this 
chiefly  happens  in  the  construction  of  storage-reservoirs  for  the 
supply  of  water  to  the  cities,  and  in  preparing  lands  for  irriga- 
tion, for  industrial  and  other  purposes.  The  calculation  of  the 
earthwork  in  these  cases  can  be  performed  in  three  different 
ways:  by  longitudinal  profile  and  cross-sections;  by  fixing  the 
grade  at  which  the  land  should  be  reduced  so  that  all  the  cuts 
may  be  employed  to  fill  in  all  the  cavities ;  and  finally  to  calculate 
directly  the  quantity  of  earth  to  be  removed  so  as  to  reduce  the 
land  to  the  required  grade. 

(1)  The  method  of  calculating  the  volume  of  earthwork  by 
means  of  longitudinal  profile  and  cross-sections  is  identical  with  the 
one  already  described.  At  first  the  topographical  survey  of  the 
land  is  made  by  ranging  on  the  ground  a  base-line  as  near  as 
possible  to  the  axis  of  the  figure.  This  is  used  in  the  same  way 
as  the  axis  of  the  construction  in  the  longitudinal  profile.  Then 
along  this  every  100,  50,  and  even  smaller  number  of  feet  apart,, 
depending  upon  the  degree  of  accuracy  required  in  the  work, 
are  erected  perpendicular  lines  and  the  various  altitudes  of  the 
points  100,  50,  25,  or  10  apart  right  and  left  from  the  axis  are 
recorded.  In  this  manner  are  made  the  various  cross-sections 


CALCULATING    QUANTITIES   AND    COST    OF    EARTHWORK.         25 

and  the  line  of  the  project  is  drawn.  The  parts  above  or  below 
this  line  represent  the  cuts  a^nd  the  fills  required  to  reduce  the 
actual  ground-surface  to  the  required  grades,  and  are  marked 
for  each  section.  The"  average  areas  of  the  cuts  or  fills  of  the 
consecutive  cross-sections  multiplied  by  their  distance  will  give 
the  volumes  of  the  cuts  and  fills  between  them.  By  calculating 
the  cuts  and  fills  required  between  all  the  various  cross-sections 
is  obtained  the  calculation  of  the  total  amount  of  earthwork 
required  for  the  work. 

This  method  is  very  simple,  and  it  is  the  one  most  commonly 
employed  on  practical  works;  and  it  may  without  great  error 
be  said  that  it  is  the  only  one  employed  in  this  country.  The 
calculation  of  the  earthwork  for  the  Jerome  Park  Reservoir  which 
is  now  under  construction  in  the  Bronx  Borough  in  connection 
with  the  water-supply  for  the  city  of  New  York  is  done  exclusively 
by  means  of  longitudinal  profile  and  cross-section  notwithstand- 
ing it  occupies  a  stretch  of  land  extending  for  nearly  1^  miles 
in  length  and  f  of  a  mile  in  width. 

(2)  But  it  may  happen  that  it  is  desired  to  know  the  elevation 
of  a  plane  at  which  the  land  should  be  reduced  in  order  that  all 
the  earth  excavated  from  the  cuts  may  be  used  to  compensate 
the  fills.  For  convenience  suppose  a  polygonal  area  ABODE, 
Fig.  12,  for  which  it  is  desired  to  find  the  altitude  of  a  plane  at 
which  all  the  cuts  and  fills  will  be  compensated.  There  is  an 
interior  poinf  0  which  is  the  highest  of  all.  Connecting  this 
point  0  with  the  various  vertices  of  the  polygon  ABODE,  the 
figure  will  be  divided  into  a  series  of  triangles  AOB,  BOO,  COD, 
DOE,  EOA.  The  altitude  of  the  various  points  being  given  as 
indicated  on  the  figure,  the  volume  of  the  earth  included  between 
a  given  datum  plane  and  the  ground-surface  will  be  given  by 
the  sum  of  all  the  triangular  prisms  having  for  bases  the  various 
triangles,  the  corresponding  edges  of  the  prisms  being  the  altitude 
from  the  given  datum  plane.  Thus,  for  instance,  the  edges  of 
the  prism  having  for  a  base  the  triangle  A  OB  will  be  3,  15,  and  5 
respectively,  while  5,  15,  and  7  will  be  those  of  the  prism  having 
for  a  base  the  triangle  BOO.  The  volume  of  all  these  various 


26 


EARTH    AND    ROCK    EXCAVATION. 


prisms  divided  by  the  total  area  of  the  polgyon  ABODE  will 
give  the  altitude  of  the  ordinate  H  of  the  horizontal  plane  of 
equal  cuts  and  fills. 


A  +3.00 


D  ooo 


5.00 


FIG.  12. 


Area  AOB 
Area  BOC 


EOA       = 


100X30 

2 
52X53 

2 

72X33 

2 
56X39 

2 

28X54.5 


Sq.  Ft. 
=  1500 


=  1092 


5921 


23 


Cu.  Ft. 


Volume,  1500X-^-  =  11,500 
o 

Volume,  1378X^  =  12,402 

o 

22 
Volume,  1188X-5-=  8>712 

o 

20 

Volume,  1087Xy=  7,246.666 

Volume,    763 X^=  5,849.666 

o 

Volume  =   45,710.332 


The  altitude  of  the  plane  of  equal  cuts  and  fills  will  be  given 
by  the  volume  divided  by  the  area,  or 

V    45,710.332 
H~A=       5921       =7'72- 


CALCULATING    QUANTITIES    AND    COST    OF    EARTHWORK.         27 

The  horizontal  plane  drawn  at  an  altitude  of  7.67  ft.  from  the 
lowest  point  D  will  intersect  the" sides  of  the  various  triangles  into 
which  the  polygon  ABODE  wa&  divided,  at  the  points  a  b  c  d  e. 
Uniting  now  these  points  with  0,  it  will  follow  that  the  area  of 
this  new  polygon  will  be  equal  to  the  sum  of  the  areas  of  the 
various  triangles  into  which  this  new  polygon  was  divided. 
Thus  we  shall  have: 

Area  boa    =   144.00 

Area  bOc   =1215.00 

Area  cOd  =    123.75 

Area  We   =     92.15 

Area  eOa  =   610.3125 


Area  of  the  polygon  abcde  =  2185.  2125 

The  altitude  of  0  above  the  plane  of  the  polygon  abcde  is  15-  H 
or  15  —  7  .  67  =  7  .  33,  and  the  volume  of  the  cuts  will  be  given  by  the 
pyramid  having  the  polygon  abcde  as  a  base  and  0  as  vertex, 
and  consequently  it  will  be 

7  33 
2185.2125  X  -V  =  5336.5358. 

o 

(3)  In  order  to  calculate  directly  the  volume  of  the  cuts 
required  to  reduce  a  tract  of  ground  to  the  required  grade, 
consider  the  former  example  and  suppose  we  are  to  reduce  the 
ground  to  the  ordinate  H  above  the  given  datum  plane  passing 
through  the  point  D.  V  being  the  actual  volume  of  the  earth 
above  the  datum  plane,  AH  will  be  the  volume  of  the  earth  which 
will  remain,  and  the  excess  to  be  hauled  away  will  be  V  —AH, 
while  the  volume  of  the  earth  to  be  used  in  filling  will  be 


For  sake  of  simplicity  suppose  we  have  an  area  of  rectangular 
shape  A  BCD,  in  which  the  various  altitudes  of  the  prominent 
points  are  marked  in  Fig.  13,  their  distances  also  being  given. 
Suppose  now  that  it  is  required  to  reduce  this  ground  to  a  hori- 
zontal plane  at  grade  with  the  point  E,  whose  ordinate  is  12  ft. 


28 


EARTH    AND    ROCK    EXCAVATION. 
N 


The  area  of  the  surface  is  3500  sq.  ft.,  and  the  volume  above 
the  given  datum  plane  after  the  work  is  done  will  be 

12A  =42,000  cu.  ft., 

70 If>  13    r» 


'M 
FIG.  13. 


while  the  actual  volume  above  the  datum  plane  is  given  by  the 
sum  of  the  various  volumes,  as  follows: 


70X21 
2 

50X28 


1  O_i_  1  O  _|_  1  K 

X-1-  -  =  700.00X13.66=  9,562.00 


2  3 

55X18.51     12+13+15 


X 

X 


2  3 

70X17.5  .  .10+12+13 

2 
50X18 

2 

47X21 
2 


=  509.02X13.33=  6,785.23 
=  612.50X11.66=  7,141.75 
=  450.00X10.66=  4,797.00 


X10+102+15=493. 50X12. 33=  6,084.85 


or    7  =  43,675.93 

We  find,  therefore,  that  the  volume  to  be  hauled  away  is 
V- 124=43,675. 93  -42,000  =  1675. 93  cu.  ft. 


CALCULATING    QUANTITIES   AND    COST    OF    EARTHWORK.         29 

By  proportion  the  vertices  of  the  broken  line  GEHI  inter- 
secting the  horizontal  plane  of  reduction  with  the  surface-ground 
are  easily  fixed.  Then  we  delermine  the  area  As  of  this  cut 
HIBCGE,  which  is 

AS  =  FIH  +  BFL  +  BCF+CEF+CEG+EFH  = 

30X19     35X14     28X50     55X18.51     55X9.4     24X24.5 

222  22  2 

=  285  +  245+700+509.02+258.5+291=2291.52  sq.  ft., 

and  the  volume  of  the  cut 

Fs  =  294. 5  +  245*  + 700|>  +  509.02f +  206. 25J  + 300. 12 
=  294.2  +  326.66+1166.66  +  678.69  +  67.83  +  294.00 

=  2828. 04  cu.  ft., 

and  the  volume  of  the  earth  to  be  used  in  filling  is 

FS-F+12A=2818.84-1675.93  =  1142.91  cu.  ft. 


CHAPTER  III. 

CUTS  AND  FILLS;    BORROW-PITS  AND  SPOIL-BANKS. 

i 

IN  many  text-books  it  is  stated  in  the  most  absolute  manner 

that  on  any  longitudinal  profile  of  earthwork  the  grade-line  should 
be  established  in  such  a  position  that  the  cuts  will  balance  the 
fills.  As  a  simple  and  practical  means  of  insuring  this  balance 
it  is  suggested  that  a  thread  stretched  in  the  hands  be  moved 
up  and  down  the  profile  until  the  portions  above  the  thread  appear 
closely  to  equal  in  area  the  portions  below  the  thread.  This 
rule  for  locating  the  grade-line  should  be  discountenanced  by 
the  engineer,  and  he  should  base  the  location  of  his  grade-line 
on  more  scientific  principles  and  independently  of  the  cuts  and 
fills.  In  many  instances,  as  will  be  shown  farther  on,  it  will  be 
found  more  convenient  to  build  up  the  fills  from  borrow-pits 
and  waste  the  material  from  the  cuts  in  spoil-banks  than  to  at- 
tempt to  compensate  one  by  the  other. 

As  a  rule  earthwork  comprises  both  cuts  and  fills.  The  earth 
excavated  from  the  cuts  may  be  utilized  to  form  the  fills,  or,  if 
not  needed  for  this  purpose,  it  may  be  wasted  at  some  convenient 
place  along  the  work,  thus  forming  what  are  commonly  called 
waste-  or  spoil-banks.  Likewise  the  fills  may  be  formed  of  the 
materials  excavated  from  the  cuts,  or  they  may  be  built  up  of 
materials  taken  from  places  near  and  alongside  but  off  the  line 
of  the  work  which  are  called  borrow-pits.  When  the  material 
taken  from  the  cuts  exactly  forms  the  fills  the  work  is  said  to  be 
compensated,  but  when  the  material  from  the  cuts  is  in  excess 
of  or  falls  below  the  amount  required  to  make  the  fills,  the  work 
is  said  to  be  done  by  spoil-banks  or  borrow-pits.  There  are, 
therefore,  two  distinct  methods  of  performing  earthwork,  viz., 

30 


CUTS  AND  FILLS;   BORROW-PITS  AND  SPOIL-BANKS.         31 

by  compensation  or  by  spoil-banks  and  borrow-pits.  Sometimes, 
however,  notwithstanding  the 'fact  that  the  volume  of  the  cuts 
equals  the  volume  of  the  fills,  tlfe  distance  between  the  cuts  and 
the  fills  may  be  so  great  that  the  long  haul  will  tend  to  increase 
greatly  the  unit  cost  of  the  work.  In  such  cases  it  is  found 
more  economical  to  perform  part  of  the  work  by  compensation 
and  part  by  spoil-banks  and  borrow-pits ;  this  gives  a  third  method 
which  is  called  the  mixed  method. 

It  is  of  the  utmost  importance  that  the  engineer  should  know 
which  of  the  three  methods  described  for  performing  earthwork 
is  the  most  economical  in  any  particular  case.  To  give  a  com- 
plete answer  to  this  problem  we  should  have  to  pass  in  review  all 
possible  cases  in  a  large  variety  of  different  forms  of  work,  which 
is  an  almost  impossible  task.  It  is  better,  therefore,  to  give 
such  general  rules  as  have  been  accepted  by  engineers  as  the 
result  of  numerous  observations,  calculations,  and  estimates. 

It  is  generally  admitted  that  it  is  more  convenient  to  com- 
pensate the  cuts  and  fills  in  the  following  cases : 

(1)  When  the  quantity  of  material  to  be  moved  from  cuts  to 
fills  is  so  large   that,   notwithstanding  the  large   investment  of 
capital  required  in  the  construction  of  roads  and  in  the  purchase 
of  plant,  the  unit  cost  of  the  filling  will  be  the  smallest  possible. 

(2)  When,   on  account  of  the  character  of  the  locality,  the 
spoil-banks   and   borrow-pits   cannot  be   located  near  the  work 
and  a  long  haul  perpendicular  to  the  line  of  the  work  is  necessary. 

(3)  When  the  land  through  which  the  work  passes  is  so  valu- 
able that  it  is  necessary  to  keep  the  area  disturbed  by  the  work 
within  the  narrowest  possible  limits. 

The  method  of  spoil-banks  and  borrow-pits  is  considered  to 
be  the  most  convenient  in  the  following  cases: 

(1)  When  the   material  taken  from  the  cut  is  so  loose   or 
treacherous  that  the  embankment  formed  of  it  would  be  neither 
stable  nor  safe. 

(2)  When  the  volume  of  cuts  and  fills  is  so  small  that  the 
roads  and  plant  required  will  increase  the  cost  of  transportation 
per  unit  of  volume. 


32  EARTH  AND  ROCK  EXCAVATION. 

(3)  When  the  value  of  the  land  occupied  by  the  work  is  nil 
or  very  small. 

(4)  When  on  account  of  the  short  time  allowed  for  the  con- 
struction of  the  work  it  is  necessary  to  prosecute  it  simultane- 
ously at  numerous  points  along  the  line. 

(5)  When  material  obstacles  such  as  mountains  or  ravines 
prevent  the  transportation  of  the  material  taken  from  the  cuts 
to  the  points  where  fills  are  necessary,  until  the  proposed  tunnels 
and  bridges  are  built,  which  is  usually  the  last  part  of  the  work. 

(6)  When  the  distance  between  the  cuts  and  fills  is  so  great 
that,  notwithstanding  the  cost  of  purchasing  the  land  for  spoil- 
banks  and   borrow-pits,  the   double  excavation  and  the  double 
volume  of  transported  material,  the  cost  of  the  work  will,  be  less 
than  if  done  by  compensation. 

It  is  impossible  to  state  absolutely  which  of  the  two  methods 
of  work  is  to  be  preferred;  the  selection  depends  upon  land  and 
special  circumstances  such  as  the  limits  of  time,  the  quantity  of 
earth  taken  from  the  excavation,  etc.  In  general  the  mixed 
method  will  be  found  cheaper  where  the  length  of  the  work  is 
considerable,  compensation  being  employed  where  the  condi- 
tions are  favorable  and  spoil-banks  and  borrow-pits  where  the 
conditions  are  unfavorable  to  compensation.  To  determine 
exactly  the  points  at  which  one  method  ceases  and  the  other 
begins  to  be  advantageous,  resort  must  be  had  to  higher  mathe- 
matics. In  actual  work,  however,  mathematical  accuracy  is  not 
required,  and  the  practice  usually  followed  is  to  determine  the 
points  named  by  trial.  Whatever  means  of  determination  is 
adopted  it  is  always  desirable  that  the  engineer  and  constructor 
should  know  in  advance  the  fills  for  which  excavation  from  cuts 
is  to  be  used  and  from  what  cuts  it  is  to  come,  and  also  the  fills 
for  which  material  from  borrow-pits  is  to  be  used  and  where  these 
borrow-pits  are  located.  This  knowledge  is  necessary  to  secure 
a  regular  and  uniform  plan  of  work,  and  is  even  more  essential 
for  determining  the  mean  length  of  haul.  It  is  impossible  to 
estimate  the  cost  of  earthwork  without  having  previously  calcu- 
lated the  mean  distance  of  haul,  for  unless  this  distance  is  known 


CUTS  AND  FILLS;  BOKROW-PITS  AND  SPOIL-BANKS. 


33 


the  cost  of  hauling,  which  is  one  of  the  most  important  cost  items 
of  the  whole  work,  cannot  be  »a6curately  determined. 

Different  methods  are  employed  for  determining  the  distribu- 
tion of  the  volumes  of  earth  along  the  profile  of  the  work.  Italian 
and  French  engineers  usually  calculate  it  algebraically,  while 
German  and  some  French  engineers  determine  it  by  graphical 
methods.  In  the  United  States  no  attention  is  paid  to  the  distri- 
bution of  volumes  along  the  line,  either  in  public  or  in  private 
works.  As  a  consequence  the  mean  distance  of  haul  is  not  known, 
and  earthwork  is  never  calculated  on  scientific  principles  in  the 
United  States.  The  author  being  aware  that  even  the  United 
States  Engineer  Corps,  which  is  in  charge  of  all  works  executed 
by  the  Federal  Government,  did  not  consider  this  factor,  requested 
the  Chief  of  Engineers  to  explain  the  reason  for  this  important 
omission,  and  received  the  evasive  answer  that  he  was  sorry  that 
he  had  no  printed  matter  for  distribution  dealing  with  this  subject. 

The  simplest  manner  of  obtaining  the  distribution  of  masses 
and  the  mean  distance  of  haul  is  that  employed  by  Italian  engi- 
neers, which  is  deduced  in  a  very  simple  manner  from  the  calcu- 
lations of  the  earthwork.  The  information  is  given  in  the  form 
of  a  table  made  up  of  ten  columns  as  follows: 


1 

ij 
§1 

fl  ^ 

Cfi  ^ 

s* 

Volumes. 

Excesses. 

Employment  of  the  Earth. 

Partial  Volumes 
of  Cuts. 

Distance  of 
Haul. 

Product  of  the 
Volume  by  the 
Distance. 

a 

3 

o 

1 
S 

3 
O 

a' 

£ 

0-1 

1-2 
2-3 
3-4 

4-5 
5-6 
6-7 

49 

'is' 
37 
63 

'19' 

si 

845 

'327 
119 

285 

560 

{90  hauled  bet.  sections  2-3 
310      "        "                  3-4 
160      "        "                   4-5 
140      "        "                   4-5 
90  taken  from  sect  ons  0-1 
310      "         "                    0-1 
(160      "         "                   1-2 
\  140      "         "                   1-2 
(240     "        "                   5-6 
j  240  brought  to  sect  ons  4—5 
\    28                                    6-7 
28  taken  from  sections  5-6 

90 
310 
160 
140 

240 

28 

77 
114 
177 
128 

19 
51 

6,930 
35,340 
28,320 
17,920 

4,560 
1,428 

187 
209 
310 

140 

90 
310 



540 

540 

320 

52 

268 

70 

98 



28 

247 

1681 

1681 

968 

968 

968 

94,498 

Referring  to  this  table  it  will  be  seen  that  in  the  first  section 
there  is  an  excess  of  560  cu.m.  of  cut,  and  between  sections  1-2  an 


34  EARTH  AND  ROCK  EXCAVATION. 

excess  of  140  cu.  m.,  while  the  fill  exceeds  the  cut  in  the  portion 
of  the  road  between  sections  2  and  5.  The  excess  of  cut  has  to  be 
brought  to  the  points  where  it  is  needed  for  fill,  and  consequently 
the  560  cu.  m.  will  be  distributed  as  follows:  90  cu.  m.  as  near  as 
possible  and  consequently  between  sections  2  and  3,  at  a  distance 
of  49  +  28  =  77  m.  ;  310  m.  between  sections  3  and  4  at  a  distance 
of  49  +  28+37  =  114  m.;  160  cu.  m.  between  sections  4  and  5  at  a 
distance  of  114  +  63  =  177  m.  Having  disposed  of  the  560  cu.  m. 
excess  of  section  0-1,  we  have  next  to  dispose  of  the  excess  of 
140  cu.  m.  of  section  1-2,  and  this  is  taken  to  section  4-5,  as 
indicated  by  the  table,  which  can  be  consulted  also  for  informa- 
tion regarding  the  procedure  for  succeeding  sections. 

French  engineers  employ  a  table  constructed  on  the  same 
principle,  but  more  complicated  in  form.  It  contains  19  col- 
umns and  considers  separately  transportation  by  wheelbarrows 
and  carts.  The  following  example  of  this  French  tabulation  is 
taken  from  Daries's  Cubature  des  Terrassements  (Table  II).  The 
figures  in  columns  1  to  5  are  obtained  from  the  calculation  of  the 
volumes  of  earth  required  for  the  work.  Those  in  column  6 
represent  the  volumes  moved  by  means  of  shovels,  and  conse- 
quently in  a  direction  transversely  to  the  axis  of  the  work.  In 
columns  7  to  10,  inclusive,  are  given  the  excesses  of  cut  and  fill 
which  have  to  be  distributed  along  the  axis  of  the  work.  Column 
11  shows  the  excess  volume  of  cut  to  be  used  as  fill,  column  12 
the  excess  volume  of  cut  to  be  wasted,  and  column  13  the  volume 
to  be  taken  from  borrow-pits.  In  column  14  are  indicated  the 
places  to  which  the  excess  volume  of  the  cuts  is  to  be  taken. 
Column  15  shows  the  lengths  of  haul;  if  this  length  is  less  than 
90  m.  the  calculations  are  placed  in  columns  16  and  17,  and  if  it 
is  greater  than  90  m.  they  are  placed  in  columns  18  and  19.  After 
the  table  is  completed  and  the  calculations  made,  if  the  work  is 
correct,  the  following  equations  should  result.  Sn  being  the 
sum  of  the  column  marked  n, 


11+  $12  +  $13  =  $16+  $13- 


CUT    AND  FILLS;   BORROW-PITS  AND  SPOIL-BANKS. 


35 


Carts  and 
Wagons. 

•aau'B^siQ  aq^ 
Aq     eauinpX      ® 
aq^  jo  s^onpojj 

rH                   rH  T^  CO           CO  rH                                                  OO 

,3ton,oA2 

C^              "^  00  CO        t^*  t^*                                      ^H 

O             CO  COO        ^  1C                                    CO 

rH                                                               C^ 

Wheelbarrow. 

Aq      saranpX      J^ 
aq^  jo  s^onpojj 

»C             O      •      •        <N           •  CO                              O 

1C                  i—  1       •       •           rH               •  CO                                          rH 

t^         o    •    •     cq^         t-                     TH_ 

cq       rn  :       c5       ^               ^ 

rH 

—AS 

1C                 I>       •       •          <M                 O5                                       CO 

»C             CO     •     •       <N             »C                             O 

^          ic    •    •    •  co         oo                     ^c 

,„,,„„«  ,<-,_  2 

i—  1  00          O  I>  <M  rH  CO  rH  <N  |> 

CO(M        CO  CO  O  00  Tt<  00  rH  00 
rH                 CO  CO<N          rH  rH 

•pa^t 
-sodaQ  aq  pmoqs  e^n^      ^ 
aq^  jo  ssaoxg  aqq.  aaaqM.      «-H 
90BTJ    aq^    jo    uon'BOipuj 

rHrH                   O  O5  00  ^  00  l>  t» 

1     Hi 

OJ        —  i  'n    <U 
02        03  §,02 

fl-    e  °°  fl  

O-  O     O  

'SaUIJ          p; 

Volumes  of 
the  Excess  of 
the  Cuts. 

•asodanj 
aaq'jo  araog  joj     ^ 
pa^tsodaQ  aq  ox 

:  :^        :  :  :  :  :  : 

:  i"5        :::::: 

a  q  ^     a  u  o  i'v      ^J 
pauaBQ    aq    ox 

1C  O5      •        CO  CO  O5  (N  Tfi  »C  1C 
Tf              •                 rH  ^  CO  TjH  rH  00 
t—  1 

Excess  of  the 
Fillings  on 
the  Cut. 

^uaoBtpv  ^H^  UI  ""* 

•       •       •              

...                                    .... 

•uorpas 
-ssoj^  qoBg[  UQ  * 

§  :  :  :              :  :  :  :|||S 

Excess  of  the 
Cut  on  Fil- 
lings. 

•suonoas-ssoj^) 
^uao'efpY'  8q^  ^1  * 

-SSOJQ  qo^g  UQ  ** 

rH                       ...           rH                       .... 

•suoi^oag  OMX 
uaaAv^aq  uoi^ioj;  aqi  ui      cc 
paAojduig  aq  o^  saumpA 

'.'.'.'.       '.    '.    '.  ^    '.    '.    '.    '.    '.  ^  w 

•uoi^oag  qo^g 
uo    saui^t^j    jo    satnnpA 

1>     •      •      •           •     •      -CD           •      •  CO  O  CO  I> 

T^        rH               .-rHTtiOO 
1C---               ...t>               .-OOSrHrH 

.       .  ^  ^ 

•  iC  CO      •           •     •      ••^f'^t1      •  Oi     •      •  *C  CO 

C<5 

qoBauoS,nojoUOa-u?nfOA- 

•  *C  CO      •            •     •        "^  "^      •  O^      *      •  *C  CO 

•  »C^        •               •       •       -O5O        %*C       •       -rHl> 
rH                                                  T—  1                       •       • 

•uot^oas-ssoj3  jo  aaqtnnK  «-• 

rHC<JCO-              -      ^      -      TflC"      CDt^OOOSO 
rH 

£ 

.s 

I 


36 


EARTH    AND    ROCK    EXCAVATION. 


The  distribution  of  the  earth  along  the  profile  may  be  calcu- 
lated graphically  by  the  curves  of  Bruckner  and  Lalanne. 

Bruckner's  Curve. — The  figure  known  as  Bruckner's  curve 
is  constructed  as  follows:  Along  a  horizontal  line  indicating  the 
longitudinal  profile  of  the  axis  of  construction  are  marked  to 
scale  the  distances  between  the  various  cross-sections  and  through 
each  point  is  drawn  a  perpendicular  line.  On  these  perpendic- 
ulars are  laid  off  the  algebraic  sum  of  the  cuts  and  fills,  the 
cuts  being  considered  as  positives  and  the  fills  as  negatives.  When 
the  result  is  positive  the  amount  is  laid  off  above  the  horizontal- 
line,  and  where  it  is  negative  the  amount  is  laid  off  below  the 
horizontal  line.  By  connecting  the  extremities  of  the  succeeding 
ordinates  by  straight  lines  or  parabolic  curves  the'resulting  figure 
forms  what  is  called  Bruckner's  curve  (Fig.  14).  This  curve  is 
constructed  upon  the  following  assumptions. 


A/               E           \B              F            G/                                        \K 

\ 

/                                          \ 

t 

V 

I                                              > 

y 

^ 

FIG.  14. 

(1)  That  each  mass  of  cuts  and  fills  is  concentrated  on  its 
corresponding  point  of  the  longitudinal  profile. 

(2)  That  on  each  cross-section  only  the  excesses  of  the  cuts 
over  the  fills,  or  vice  versa,  are  recorded,  and  consequently  the 
volume  of  earth  transferred  from  cut  to  fill  by  shovel  is  not  con- 
sidered. 

Bruckner's  curve  possesses  a  number  of  important  properties 
which  may  be  summarized  as  follows: 

(1)  The  maximum  and  minimum  of  the  curve  correspond  to 
the  points  at  grade  where  the  cut  ends  and  the  fill  begins,  or 
vice  versa;  thus  the  points  M  and  N  (Fig.  13)  are  points  at  grade. 

(2)  The  nature  of  the  work  is  the  same  in  the  space  between 
a  maximum  and  a  succeeding  minimum,  and  is  always  cut;   it  is 


OF  THE 


CUTS  AND  FILLS;  BORROW-PITS  AND  SPOIL-BANKS.         37 

also  the  same  between  a  minimum  and  a  succeeding  maximum 
and  is  always  fill.  Thus  in  Fig.  13  the  work  between  A  and  M 
is  cut,  E  and  F  being  points  at  £rade. 

(3)  The   base-line  detaches  from   the  curve  segments  whose 
bases  represent  sections  of  line  in  which  the  cuts  and  fills  are 
compensated.     Thus  the  cuts  equal  the  fills  for  the  section  of 
line  AB,  and  the  common  volume  is  represented  by  the  line  EM. 

(4)  Considering  any  section  AB    in  which  the  fills  MB  are 
made  with  materials  taken  from  the  cuts  AM,  the  surface  AMB 
represents  the  sum  of  the  moments  of  the  corresponding  haul 
(products  of  the  volumes  by  the  distance). 

Property  No.  3  of  the  curve  indicates  a  method  of  distributing 
along  the  axis  of  the  construction  the  materials  obtained  from 
the  cuts.  But  since  this  solution  is  possible  for  every  line  parallel 
to  the  ground-line  and  each  one  will  give  a  new  distribution  of 
the  earth,  among  the  infinite  solutions  must  be  selected  the  one 
which  requires  the  minimum  of  transportation.  In  giving  the 
line  of  distribution  two  conditions  must  be  observed: 

(1)  That  the  sum  of  the  surfaces  of  the  segment  separated  by 
this  line  on  the  curve  be  the  minimum. 

(2)  That  the  volume  of  materials  taken  from  borrow-pits  or 
deposited  on  the  spoil-banks  must  not  be  increased. 

Several  cases  may  happen.  The  curve  of  Bruckner  ends  at 
the  ground-line,  or  else  it  ends  either  above  or  below  the  ground- 
line.  If  the  extreme  of  the  curve  ends  at  the  ground-line  this 
is  the  line  of  distribution  of  the  masses.  But  if  the  curve  of 
Bruckner  ends  above  or  below  it,  from  the  free  end  of  the  curve 
is  drawn  a  horizontal  line.  Afterward  are  calculated  the  respec- 
tive sums  of  the  chords  intercepted  by  the  ground-line  in  the 
segments  that  increase  and  decrease  in  a  plan  toward  the  free 
end  of  the  polygon;  if  the  first  sum  is  greater  than  the  second 
then  the  ground-line  is  the  line  representing  the  'distribution  of 
the  volumes;  otherwise  the  line  is  raised  up  or  lowered  until  the 
sums  of  the'  opposite  segments  are  equal.  The  position  of  the 
lines  satisfying  such  a  condition  is  the  line  of  the  distribution  of 
the  volumes;  but  when  it  is  not  satisfied  before  the  free  end  of 


38 


EARTH    AND    ROCK    EXCAVATION. 


the  curves  is  reached,  then  from  this  extreme  is  drawn  a  horizon- 
tal line,  and  this  will  be  the  line  of  the  distribution  of  the  masses. 

Lalanne's  Curve. — This  is  the  only  graphical  method  em- 
ployed by  French  engineers  for  calculating  the  distribution  of 
the  earths  along  the  longitudinal  profile  of  the  construction  as 
well  as  the  mean  distance  of  hauling.  It  is  older  than  the  Bruck- 
ner curve  and  it  can  be  considered  as  a  modification  of  this 
notwithstanding  it  is  simpler  and  is  based  on  the  same  principle. 
Also  in  this  case  the  ordinates  represent  the  algebraic  sum  of  the 
volumes  of  cuts  and  fillings,  the  cuts  being  considered  as  positive 
and  the  fillings  as  negative.  The  upper  points  of  the  various 
ordinates  instead  of  being  connected  by  means  of  straight  lines 
or  parabolic  curves  as  in  the  Bruckner  method  are  connected 
by  horizontal  lines  drawn  parallel  to  the  ground-line.  The  so- 
called  Lalanne's  curve  is  really  composed  of  a  series  of  parallelo- 
grams above  or  below  the  ground-line,  and  it  is  very  convenient 
for  the  location  of  the  line  of  distribution  and  the  calculation  of 
the  mean  distance  of  hauling. 

In  Fig.  15,  representing  Lalanne's  curve  as  given  by  Daries, 
he  says  that  the  volume  BA  of  the  cut  should  be  carried  on  the 
equivalent  volume  Nh  of  fillings,  and  the  mean  distance  for  this 
partial  hauling  is  Ah.  If  the  hauling  is  smaller  than  90  m.  bar- 


J 

01 

_> 

G 

71 

h 

y                                   P 

c                 ' 

—  > 

1 

2 

S 
V 

FIG.  15. 


rows  will  be  employed,  otherwise  the  material  will  be  transported 
by  means  of  carts  and  wagons.  Also  the  volume  mC  of  cuts 
must  fill  in  the  equivalent  volume  Gn  of  fillings,  and  the  partial 
mean  distance  of  hauling  is  dh. 


t  CUTS  AND  FILLS;   SORROW-PITS  AND  SPOIL-BANKS.         39 

When  Lalanne's  curve  ends  above  the  ground-line,  there  is 
an  excess  LI  of  fillings,  which  ^"necessary  to  build  with  materials 
taken  from  borrow-pits,  but  wrjgn  the  line  of  the  curve  ends  on 
the  ground-line  this  is  tne  line  of  distribution  of  the  volumes  and 
the  work  will  then  be  compensated. 

The  mean  distance  at  which  the  materials  ought  to  be  hauled 
is  usually  calculated  according  to  the  following  methods: 

(1)  By  the  horizontal  distance  of  the  projections  of  the  centers 
of  gravity  of  the  cuts  and  fillings. 

(2)  By  the  moment. 

(3)  By  Bruckner's  and  Lalanne's  curves. 

By  the  Projection  of  the  Centers  of  Gravity. — The  geometrical 
position  of  the  centers  of  gravity  of  the  cuts  and  fillings  can  be 
easily  deduced  from  the  longitudinal  profile  and  cross-sections 
in  the  following  manner.  On  a  horizontal  line  lay  off  the  dis- 
tances of  the  various  cross-sections,  erect  perpendiculars  and 
on  these  take  segments  representing  the  excess  of  the  cut  or 
filling  in  the  same  cross-section;  the  segments  indicating  the  cuts 
are  marked  above  the  horizontal  line  and  those  representing  the 
fillings  below.  Unite  all  the  points  of  the  cuts  and  those  of  fill- 
ings, find  the  centers  of  gravity  of  these  two  figures,  and  the 
horizontal  distance  of  their  projection  will  represent  in  scale  the 
mean  distance  of  hauling.  Only  the  difference  between  the 
cuts  and  fillings  on  the  same  section  is  marked  here,  because  the 
earth  removed  from  the  cut  and  used  for  filling  on  the  same  sec- 
tion is  not  removed,  and  consequently  it  is  only  the  surplus  that 
must  be  hauled  away. 

The  same  result  could  be  directly  obtained  from  the  graphical 
representation  of  the  volumes  of  earthwork,  as  given  on  p.  23. 
By  revolving  the  figures  around  the  horizontal  line  and  omitting 
the  overlapping  portions,  which  means  to  eliminate  the  areas  of 
cuts  and  fillings  compensated  on  the  same  cross-section,  then  the 
horizontal  distance  of  the  projections  of  the  centers  of  gravity  of 
the  remaining  areas  will  be  the  mean  distance  of  hauling. 

The  horizontal  distance  of  the  projections  of  the  centers  of 
gravity  of  the  cuts  and  fillings,  however,  represents  the  mean 


40  EARTH  AND  ROCK  EXCAVATION. 

distance  of  hauling  only  in  case  that  the  cuts  and  fillings  are 
compensated.  But  when  the  cuts  are  in  excess  of  the  fillings  or 
vice  versa,  and  consequently  the  part  in  excess  must  be  deposited 
in  the  waste-banks  or  taken  from  borrow-pits,  the  mean  distance 
of  hauling  will  then  be  given  by  the  averages  of  the  horizontal 
distance  of  the  centers  of  gravity  of  the  portions  that  are  com- 
pensated and  the  horizontal  distance  of  the  projection  of  the 
centers  of  gravity  of  the  excess  of  the  cut  and  the  spoil-bank  as 
the  defect  of  the  cut  and  borrow-pit. 

By  Moments. — The  second  manner  of  calculating  the  mean 
distance  of  hauling  is  by  moments.  The  name  is  borrowed  from 
the  mechanic,  and  means  in  this  case  the  quantity  of  volume  of 
earthwork  included  within  two  consecutive  cross-sections  mul- 
tiplied by  the  distances  at  which  this  partial  volume  must  be 
hauled.  The  mean  distance  of  hauling  will  be  obtained  by  the 
quotient  of  the  sum  of  the  moments  of  hauling  divided  by  the 
sum  of  the  hauled  volumes. 

On  the  application  of  this  principle  the  mean  distance  can  be 
correctly  calculated  by  a  very  long  process;  but  since  in  practical 
works  the  promptness  of  a  method  is  always  preferred  to  great 
mathematical  accuracy,  the  mean  distance  of  the  hauling  is 
obtained  from  the  tables  already  given  and  especially  constructed 
in  order  to  know  the  distribution  of  the  various  masses  of  the 
earth  along  the  line  of  the  work. 

According  to  the  table  used  by  the  Italian  engineers,  illus- 
trated at  p.  33,  the  mean  distance  of  hauling  is  obtained  by  the 
sum  of  the  numbers  in  column  10,  representing  the  partial  products 
of  the  volumes  to  be  removed,  multiplied  by  the  distance  at  which 
they  ought  to  be  hauled.  Such  a  total,  which  in  the  case  here 
considered  is  94,498,  must  be  divided  by  the  sum  of  the  num- 
bers in  column  8,  representing  the  partial  volumes  968.  In 

94  498 
this  case  the  mean  distance  of  hauling  will  be      '       =  97  meters. 

French  engineers  considering  separately  the  hauling  done  by 
means  of  wheelbarrow  and  that  done  by  cart  and  wagon,  two 
different  mean  distances  are  obtained,  the  one  for  the  barrow, 


CUTS  AND  FILLS;   BORROW-PITS  AND  SPOIL-BANKS.         41 

and  the  second  for  the  cart.  In  both  cases,  however,  the  mean 
distance  of  hauling  is  given  by  the  sum  of  the  products  of  the  par- 
tial volumes  by  their  distance,  divided  by  the  sum  of  the  partial 
volumes.  Thus  the  quotient  of  the  numbers  in  columns  16  and 
17,  2503  and  148,110  respectively,  being  59,  will  represent  in 
meters  the  mean  distance  of  hauling  by  wheelbarrow;  and  the 
quotient  of  the  numbers  in  columns  18  and  19,  2361  and  282,934 
respectively,  being  205,  will  give  the  mean  distance  of  hauling 
by  cart  and  wagon. 

By  Bruckner  and  Lalanne's  Curves. — Both  curves  have  been 
already  explained  at  length,  and  consequently  any  further  expla- 
nation will  be  useless.  The  area  limited  by  the  perimeter  of  the 
curve  of  Bruckner  and  the  horizontal  ground-line  represents  the 
moment  of  hauling  of  the  volumes  multiplied  by  the  greatest 
ordinate,  or  the  product  of  the  volume  multiplied  by  the  mean 
distance ;  and  consequently  the  mean  distance  of  hauling  is  given 
by  the  total  area  divided  by  the  greatest  ordinate. 

Similarly  with  the  Lalanne's  curve.  Here  the  heights  of  the 
parallelograms  are  respectively  equal  to  the  algebraic  sum  of 
the  cuts  and  fillings,  while  the  bases  of  the  parallelograms  repre- 
sent the  partial  distance  of  hauling.  In  this  case  also  the  gen- 
eral mean  distance  of  hauling  to  be  used  in  calculations  will  be 
given  by  the  total  area  divided  by  the  greatest  ordinate. 


CHAPTER  IV. 

CLASSIFICATION   OF  MATERIALS;    ROCK  EXCAVATION  WITHOUT 

BLASTING. 

CLASSIFICATION   OF   MATERIALS. 

THE  operation  of  destroying  the  cohesion  of  the  earthy  mate- 
rials in  order  to  remove  them  from  their  natural  bed  in  the  exe- 
cution of  work  is  termed  excavation.  These  materials  oppose 
a  resistance  to  being  moved  which  varies  greatly  with  their  nature. 
Some  of  them,  as  quicksand  and  mud,  oppose  little  if  any  resist- 
ance, while  others,  as  rock  and  indurated  clay,  oppose  a  very 
strong  resistance.  On  the  basis  of  resistance  offered  to  excavation 
the  earthy  materials  may  be  divided  into  two  broad  classes, 
earth  and  rock.  On  the  same  basis  it  is  customary  to  divide 
both  earth  and  rock  into  several  subclasses. 

Earth  is  usually  divided  into  very  loose  soils,  loose  soils,  and 
friable  soils.  The  very  loose  soils  are  those  which  have  so  little 
cohesion  that  they  offer  practically  no  resistance  to  being  Sepa- 
rated from  their  natural  bed,  and  may  be  removed  by  shovels; 
they  are  sand,  mud,  quicksand,  peat,  etc.  Loose  soils  are  those 
which  have  sufficient  cohesion  to  make  a  stronger  tool  than  a 
shovel  necessary;  the  spade  is  necessary  for  their  excavation. 
Clay,  shale,  gravel,  and  some  sands  belong  to  this  group.  The 
friable  soils  are  those  which  require  a  sharp-pointed  tool  to  break 
them  up;  the  pick  is  the  tool  used  in  their  excavation.  Indurated 
clay,  disintegrated  rock,  volcanic  deposits,  and  agglomerated 
sands  are  considered  friable  soils. 

Rock-like  earth  may  be  divided  into  three  classes  upon  the 
basis  of  its  resistance  to  excavation;  these  classes  are  soft  rocks, 
rocks  of  ordinary  consistency,  and  hard  rocks.  Soft  rocks  are 

42 


CLASSIFICATION    OF   MATERIALS. 


43 


those  easily  moved  by  iron  bars  and  wedges,  and  they  comprise 
the  slates  and  other  stratified  and  easily  split  stones.  The  rocks 
of  ordinary  consistency  are  such, as  can  be  removed  by  iron  bars, 
sledges,  and  channeling-machiries,  and  among  them  are  sand- 
stones and  various  micaceous  and  talcose  rocks.  The  hard  rocks 
are  those  of  such  hardness  and  toughness-  that  none  of  the  tools 
mentioned  are  capable  of  breaking  them  up  and  blasting  has  to 
be  resorted  to.  Generally  in  engineering  work  the  softer  rocks, 
which  are  capable  of  being  excavated  by  tools,  are  blasted  to 
shorten  the  time  of  excavation. 

Because  of  the  different  degrees  of  resistance  which  different 
materials  offer  to  excavation,  the  time  required  per  unit  volume 
for  their  excavation  differs.  These  times  are  usually  expressed 
in  functions  of  a  day's  work,  which  is  assumed  to  be  ten  hours, 
and  by  multiplying  these  numbers  by  the  daily  average  of  the 
workmen  the  cost  of  excavation  per  unit  volume  is  at  once  known. 
The  values  of  these  functions  are  usually  assumed  to  be  as  follows: 

Very  loose  soils,  including  loading 0 . 07  to  0 . 09 

Loose  soils,  excavation  only 0. 13  to  0. 18 

Friable  soils,       "        "         0.20  to  0. 25 

Soft  rock,  "        "         0.35  to  0.50 

Ordinary  rock,    "        "        0.75  to  1 .00 

Hard  rock,          "        "         1.2    to  1.5 

These  figures  serve  merely  to  give  a  general  idea  of  the  time 
employed  for  excavating  a  unit  volume;  the  engineer  must 
make  special  estimates  for  any  particular  case.  It  is  needful 
to  note  also  that  these  data  are  for  materials  excavated  in  the 
open  air,  and  must  be  modified  when  the  excavation  is  done  under 
difficult  circumstances,  as,  for  example,  in  tunnels,  deep  trenches, 
and  shafts.  For  work  done  in  tunnels  the  above  coefficients 
should  be  multiplied  by  1.5  for  earth  and  by  from  2  to  3  for  rock. 

In  sinking  shafts,  where  the  work  is  still  more  difficult,  the  above 
coefficients  should  be  doubled.  In  trenching,  although  the  work 
is  done  in  the  open  air,  a  change  of  the  coefficients  given  is  neces- 
sary, but  it  is  difficult  to  say  definitely  how  great  this  should  be, 


44  EARTH  AND  ROCK  EXCAVATION. 

since  local  circumstances,  such  as  the  depth  and  narrowness  of 
the  trench,  have  a  great  influence.  It  can  be  assumed  in  a  general 
way,  however,  that  for  trenches  of  ordinary  size  and  depth 
these  coefficients  should  be  increased  by  quantities  ranging  from 
one-third  to  one-fourth  of  their  value.  Water  increases  the  diffi- 
culty of  excavation  in  trenches,  and  where  surface-water,  small 
springs,  or  seepage  are  present  the  coefficients  given  should  be 
increased  about  15  per  cent. 

In  earthwork  the  quantities  are  always  measured  on  the 
material  in  its  original  bed,  and  the  coefficients  which  have  been 
considered  above  refer  to  materials  so  measured.  A  cubic  yard 
of  earth  or  rock  in  its  natural  bed  makes  considerably  more  than 
a  cubic  yard  of  excavated  material;  generally  speaking,  the  in- 
crease in  volume  is  proportional  to  the  resistance  offered  to  ex- 
cavation. It  can  be  assumed  as  a  general  rule  that  for  earth  the 
increase  is  from  20  to  25  per  cent.,  and  for  rock  from  30  to  40 
per  cent. 

The  excavation  of  either  earth  or  rock  can  be  done  by  hand 
or  by  machine.  In  this  and  the  succeeding  chapters  the  tools 
and  machines  employed  in  earth  and  rock  excavation  are  de- 
scribed and  their  use  and  operation  explained. 

ROCK   EXCAVATION   WITHOUT  BLASTING. 

From  the  early  days  of  human  civilization  until  very  re- 
cently the  excavation  of  rock  was  accomplished  solely  by  means 
of  hand-tools.  Thus  all  the  cut  stones  that  were  employed 
over  6000  years  ago  in  the  construction  of  the  •  Pyramids  and 
other  Egyptian  monuments,  as  well  as  the  large  stones  used  in 
the  construction  of  the  cyclopean  walls  which  surrounded  the 
prehistoric  cities  of  Greece  and  Italy,  were  excavated  by  hand. 
For  mining  and  engineering  purposes,  however,  the  excavation 
of  rock  was  facilitated  by  suddenly  cooling  with  water  surfaces 
which  had  been  previously  heated  by  fire.  On  account  of  the 
sudden  change  in  temperature  cracks  were  produced  which 
afforded  points  of  attack  by  wedges  and  other  sharp  tools.  Fire- 


ROCK    EXCAVATION   WITHOUT    BLASTING.  45 

setting,  as  this  operation  was  termed,  was  the  only  means  of 
rock  excavation,  aside  from  Jiahd-tools,  which  was  employed  up 
to  the  early  part  of  the  eighteenth  century,  as  old  engravings 
illustrating  the  mining  operations  of  that  time  clearly  indicate. 
It  is  still  employed  for  breaking  small  boulders  in  contract 
work,  and  the  author  has  witnessed  its  use  on  a  large  scale  at 
the  calcedony  quarries  near  Sant  Antonino  di  Susa  in  Italy  to 
break  up  the  rocks  for  the  stone-crushers  in  making  fire-proof 
bricks. 

In  1613  the  art  of  rock  excavation  was  revolutionized  by  the 
introduction  of  blasting.  In  that  year  gunpowder,  which  up  to 
that  time  had  been  used  for  artillery  and  other  military  pur- 
poses exclusively,  was  employed  by  a  chief  mining  boss  at 
Freiburg  in  Germany,  for  blasting  the  ore-bearing  rock  in  the 
mines  under  his  charge.  Blasting  by  gunpowder  was  employed 
exclusively  until  the  second  half  of  the  last  century,  when  the 
discovery  of  nitroglycerine  and  its  derivatives  gave  a  more  power- 
ful explosive  which  has  largely  replaced  gunpowder,  although 
the  latter  is  still  used. 

Rock  may  be  excavated  in  two  ways:  (1)  directly,  by  hand- 
tools  and  machine-cutting,  and  (2)  indirectly,  by  blasting.  Soft 
rocks  and  thin  stratified  rocks  are  generally  excavated  by  hand- 
tools;  it  is  only  recently  that  rock-cutting  machines  have  been 
generally  employed.  For  excavating  hard  rock  blasting  is  prac- 
tically universal.  In  blasting,  which  is  the  process  of  shattering 
rock  by  the  sudden  generation  of  a  large  volume  of  gases  in  an 
enclosed  space,  several  separate  operations  are  required,  viz., 
boring  the  holes,  charging  them  with  the  explosive,  tamping  the 
opening,  and  firing  the  charge.  The  holes  are  bored  to  receive 
the  charge,  and  the  charge  is  the  explosive  matter  from  which 
the  gases  are  developed ;  the  tamping  or  closing  of  the  holes  above 
the  charge  prevents  the  gases  from  escaping  without  shattering 
the  rock,  and  the  firing  is  the  act  of  igniting  the  explosive. 

When  rock  is  excavated  by  directly  removing  it  from  its 
natural  bed  by  means  of  hand-tools  or  cutting-machines  the  tools 
most  commonly  employed  are  picks,  crowbars,  drill  and  hammer, 


46  EARTH  AND  ROCK  EXCAVATION. 

sledge-hammers,  wedges,  and  the  plug  and  feather;  the  only 
cutting-machine  used  in  the  excavation  of  rock  for  public  works 
is  the  channeling-machine. 

Pick. — The  pick  employed  by  the  quarryman  is  similar  to 
the  one  employed  in  the  excavation  of  earth;  it  may  have  both 
ends  pointed  or  one.  end  may  have  a  chisel  edge.  The  points 
being  wedge-shaped  permit  the  tool  to  penetrate  the  joints  or 
seams  of  fissured  rock  or  between  the  laminae  of  thinly  stratified 
rocks,  such  as  slates  and  shales.  When  its  point  has  been  forced 
into  the  rock  the  pick  is  used  as  a  lever  to  increase  the  fracture  by 
prizing  upon  the  handle.  Thus  the  action  of  the  pick,  as  Mr. 
Lock  says,  embodies  the  actions  of  the  hammer,  the  wedge,  and 
the  crowbar.  It  acts  as  a  hammer  in  delivering  a  blow,  as  a 
wedge  in  penetrating  and  disrupting  the  rock,  and  as  a  crowbar 
or  lever  in  forcing  out  large  masses.  When  one  of  the  points  is 
chisel-edged  the  pick  is  used  for  cutting  off  the  projecting  corners 
and  chips  to  smooth  the  walls  of  the  excavation,  but  properly 
speaking  it  is  not  then  an  excavat ing-tool. 

Crowbars. — The  crowbar  (Fig.  16)  consists  of  an  iron  rod, 
an  inch  or  more  in  diameter  and  5  or  6  ft.  long,  which  has  one 
end  shaped  to  a  chisel  edge  and  the  other  end  bent  to  permit  its 
use  as  a  lever.  Crowbars  are  used  in  excavating  fissured  or 
thinly  stratified  rocks.  In  operation  the  chisel  edge  is  forced 
into  the  seams  or  between  the  strata,  and  the  -  bar  is  swung  back 
and  forth,  enlarging  the  opening.  When  the  crevice  is  large 
enough  the  bar  is  reversed  and  the  bent  end  inserted,  after  which 
the  swinging  back  and  forth  is  continued  until  the  fragment  of 
rock  is  detached  from  its  bed. 

Sledge-hammers  and  Wedges. — Rock  is  frequently  excavated 
by  means  of  sledge-hammers  and  wedges.  The  sledge-hammer 
(Fig.  17)  consists  of  a  parallelopipedon  of  iron  with  its  extremities 
hardened,  and  having  an  eye  at  the  center.  Its  weight  varies 
from  30  Ibs.  to  50  Ibs.,  and  a  wooden  handle  from  2J  ft.  to  3  ft. 
long  is  inserted  in  the  eye.  The  blow  which  can  be  struck  with 
an  implement  of  this  character  is  very  powerful.  The  sledge- 
hammer may  be  used  alone  or  in  connection  with  a  wedge.  They 


ROCK    EXCAVATION   WITHOUT   BLASTING. 


47 


are  used  alone  for  breaking  masses  of  stone  which  have  already 
been  separated  from  their  natural  bed,  and  with  wedges  where 
the  purpose  is  to  separate  a  mass  of  rock  from  its  bed.  In  break- 
ing stones,  if  they  are  of  moderate  dimensions  they  are  placed  so 
as  to  be  supported  at  the  two  ends,  while  the  blow  is  delivered  on 
the  center.  As  a  rule  several  blows  are  required,  and  each  should 
be  delivered  on  the  same  spot  and  at  right  angles  to  the  quarry- 
bed.  To  break  up  rocks  too  large  to  be  handled  as  just  described 

O 


aO  6 

FIG.  16. 


FIG.  17. 


the  projecting  corners  are  first  sledged  off,  and  then  a  succession 
of  blows  delivered  on  the  center  of  the  remaining  mass  until  it 
flies  to  pieces  from  the  shock;  or,  if  the  mass  is  very  large,  it  is 
split  by  means  of  the  wedge. 

Wedges  of  the  form  shown  by  Fig.  18  are,  as  a  rule,  made  of 
iron  and  are  about  1  ft.  long  and  have  a  head  3X6  ins.;  but 
sometimes,  especially  in  the  excavation  of 
very  soft  and  thinly  stratified  rocks,  they  are 
made  of  wood  and  with  very  much  larger 
dimensions.  Wedges  are  used  mostly  in  cutting 
the  rock  from  its  natural  bed,  and  the  mode 
of  procedure  of  this  work  is  as  follows :  A  slot 
is  first  cut  in  the  rock  by  means  of  a  pick  or  FlG-  18- 

crowbar,  and  the  wedge  is  inserted  in  this  slot  and  driven  home 


48  EARTH  AND  ROCK  EXCAVATION. 

by  blows  with  the  sledge-hammer.  By  cutting  a  long  slot,  inserting 
a  number  of  wedges  at  intervals  and  driving  them  simultaneously 
the  rock  can  be  split  along  a  given  line,  and  blocks  of  any  dimen- 
sions ordinarily  required  thus  broken  out.  Wedges  are  found 
most  serviceable,  however,  when  the  dip  of  the  rock  is  such  as 
to  permit  their  insertion  between  the  strata  so  that  the  rock  is 
split  along  its  natural  cleavage-lines. 

Plug  and  Feathers. — For  removing  rock  in  blocks  the  plug 
and  feather  is  a  more  satisfactory  implement  than  a  wedge.  This 
method  of  excavation  belongs  more  properly  to  quarrying  than 
to  ordinary  excavation,  but  as  in  most  engineering 
works  where  rock  excavation  is  required  there  is 
masonry  work  which  requires  stones  of  regular 
shape,  it  is  described  here.  The  first  operation  is 
to  drill  a  row  of  holes  spaced  at  intervals  along  the 
line  of  the  intended  fracture.  These  holes  may  be 
drilled  by  hand  or  power  drills,  exactly  as  are  holes 
for  blasting  as  described  in  a  succeeding  chapter,  but 
they  are  drilled  only  about  a  foot  deep.  In  each 
hole  are  placed  two  feathers  which  are  made  of 
half-round  wrought  iron  and  is  the  form  shown  by 
Fig.  19.  The  plug  is  a  piece  of  steel  of  the  form  of 
a  truncated  wedge,  and  it  is  placed  between  the 
feathers  (Fig.  19)  and  driven  tight.  When  the  plug  and  feathers 
have  been  started  in  all  the  holes,  the  plugs  are  driven  down 
simultaneously  by  light  blows  until  the  rock  splits  along  the  line 
of  holes. 

Channeling-machine. — The  channeling-machine  is  a  machine 
for  cutting  vertical  slots  or  channels  in  rock,  and  a  view  of  such 
a  device  at  work  is  shown  by  Fig.  20.  A  vertical  boiler  is  mounted 
on  a  car  and  supplies  steam  to  a  vertical  cylinder,  the  piston-rod 
of  which  projects  downward  and  carries  a  sort  of  cross-head  to 
which  are  clamped  the  various  cut  ting- tools.  The  car  travels 
back  and  forth  on  a  track  parallel  and  close  to  the  proposed  cut, 
which  is  made  by  the  tool  or  chisel  receiving  a  reciprocating 


ROCK    EXCAVATION   WITHOUT    BLASTING.  49 

motion  from  the  motion  of  the  piston  in  the  steam-cylinder.  The 
width  of  channel  cut  is  usually  2j  ins.  at  the  top  and  1J  ins.  at 
the  bottom,  the  taper  being  fgund  desirable  in  removing  the 
chips  and  dust,  which  'soon  obstruct  the  tool  by  accumulation 
unless  gotten  rid  of.  This  is  frequently  accomplished  by  flushing 
the  channel  with  a  jet  of  water.  The  cutting-bars  used  are  of 
different  lengths;  the  shortest  is  2  ft.  10  ins.,  and  it  will  cut  a 


/ 


FIG.  2Q. 


18  ins.  deep,  and  the  others  increase  in  length  successively, 
each  cutting  the  slot  18  ins.  deeper  than  the  preceding.  The  edges 
of  these  tools  are  shaped  in  different  ways  according  to  the  mate- 
rial to  be  channeled,  and  they  are  provided  with  shanks  1  in. 
thick  and  6  ins.  wide,  by  which  they  are  attached  to  the  cross- 
head.  The  largest  cutter  employed  with  this  machine  is  88  ins. 
long,  so  that  the  rock  must  be  excavated  in  trenches  from  7  ft. 
to  8  ft.  deep.  The  work  of  the  channeling-machine  frees  the 
rock  from  its  natural  bed, 'but  only  on  its  vertical  sides;  to  free 
it  from  the  bottom  other  means  have  to  be  adopted.  For  this 
purpose  wedges  are  used,  they  being  driven  between  the  strata 


50  EARTH  AND  ROCK  EXCAVATION. 

if  the  rock  lies  in  horizontal  layers,  or  into  the  holes  formed  by  a 
gadder  if  the  rock  is  not  stratified  horizontally.  The  gadder 
is  a  machine  by  which  a  row  of  horizontal  holes  can  be  bored  in 
line  with  the  flow  of  the  cutting. 

The  efficiency  of  the  channel  ing-machine  varies  of  course  with 
the  character  of  the  rock  being  worked.  In  uniform  sandstones 
it  will  cut  about  500  sq.  ft.  of  channel  per  day;  in  marble  it  will 
cut  from  70  to  125  sq.  ft.  per  day.  In  the  excavation  of  the 
Chicago  Drainage  Canal,  where  channeling-machines  were  em- 
ployed for  the  first  time  on  a  large  public  work,  their  capacity 
ranged  from  50  sq.  ft.  per  day  in  the  moist  material  to  500  sq.  ft. 
in  the  hardest  and  most  homogeneous  rock.  It  has  been  found 
by  experiment  that  the  most  satisfactory  depth  of  cut  is  between 
6  and  10  ft.,  although  this  is  considerably  more  than  the  average 
depth  in  quarrying. 

Channeling-machines  are  built  by  the'  Sullivan  Machinery 
Company  of  Chicago,  111.,  and  the  Ingersoll-Sergeant  Drill  Com- 
pany of  New  York,  N.  Y.  The  features  of  merit  claimed  by 
the  makers  and  apparently  proved  in  the  construction  of  the 
Chicago  Drainage  Canal  are  convenience  in  operation,  economy 
in  fuel  consumption,  and  efficiency.  The  cost  of  running  a  channel- 
ing-machine  on  this  work  was  given  by  Engineering  News  as 
follows : 

Wages  of  driver $2 . 75 

Wages  of  fireman. 1 . 75 

Wages  of  helper 1 . 50 

Blacksmith  and  team  for  hauling  drills 0 . 68 

Superintendence 1 . 33 

Cost  of  coal  delivered  to  machine 2 . 50 


Total $10.51 

The  cost  of  working  may  be  approximately  learned  from  the 
following  figures,  referring  to  a  fairly  representative  month's 
operation  of  an  Ingersoll-Sergeant  channeler  on  the  Chicago 
Drainage  Canal: 


ROCK   EXCAVATION   WITHOUT    BLASTING.  51 

Driver's  wages $80 . 10 

Helper's  wages 4 . •; 39.30 

Foreman's  wages > 48 . 58 

Coal..  80.00 


Total $247.98 

Square  feet  channeled 4,020 

From  these  figures  the  cost  amounts  to  about  5  cents  per 
square  foot.  This  does  not  include  the  cost  of  blacksmith's 
work  in  sharpening  tools;  adding  this  and  such  other  items  as 
oil,  stores,  etc.,  the  cost  of  the  channeling  work  appears  to  have 
averaged  8J  cents  per  square  foot,  or  2.8  cents  per  cubic  yard  of 
excavation  between  the  channels  on  opposite  sides  of  the  canal. 
All  the  other  items,  as  repairs,  interest  on  capital,  sinking  fund, 
etc.,  it  may  be  safely  assumed  that  the  cost  of  channeling  was 
3  cents  per  cubic  yard  of  material  excavated. 


CHAPTER  V. 

EXCAVATION   OF  ROCK   BY  BLASTING:    THE  DRILLING  OF  THE 

HOLES. 

THE  excavation  of  rock  for  the  execution  of  public  works  is 
usually  done  by  blasting.  Blasting,  as  has  already  been  explained, 
is  the  operation  of  shattering  rock  by  the  instantaneous  generation 
of  a  large  volume  of  gas  in  a  confined  space.  Several  different 
operations  are  required  in  blasting  rock;  the  first  is  the  drilling 
of  holes  into  the  rock,  the  second  is  the  charging  of  these  holes 
with  an  explosive,  the  third  is  the  closing  of  the  holes  by  tamping, 
and  the  fourth  is  the  firing  or  ignition  of  the  charge.  These  oper- 
ations are  described  and  explained  in  this  and  the  two  succeeding 
chapters. 

HAND-DRILLING. 

The  drilling  of  the  holes  for  blasting  operations  may  be  done 
either  by  hand  or  by  machine-drills.  Hand-drilling  is  employed 
where  the  quantity  of  rock  excavated  is  so  small  that  it  will  not 
pay  to  instal  a  power  plant  and  employ  machine-drills.  The 
excavation  of  small  trenches  for  pipes  and  conduits  under  city 
streets  is  an  example  of  such  a  case.  The  tools  used  in  drilling 
by  hand  are  crowbars  and  hand-drills  and  hammers. 

Crowbars. — The  crowbar  used  in  drilling  is  substantially  simi- 
lar to  the  one  used  in  excavating  rock  without  blasting,  which 
has  already  been  described.  It  is  a  steel  rod  1J  ins.  in  diameter 
and  from  5  to  7  ft.  long,  the  two  ends  of  which  are  sharpened  to 
a  chisel  edge.  The  manner  of  operating  the  bar  in  drilling  is  to 
raise  it  and  let  it  fall  vertically,  turning  it  slightly  in  the  hand  at 
each  blow.  The  continued  repetition  of  blows  drills  the  hole. 

52 


THE    DRILLING    OF   THE    HOLES.  53 

The  chisel  edge  is  made  about  1  in.  wider  than  the  diameter  of 
the  shaft  of  the  bar,  so  that  the  .-hole  will  be  cut  large  enough  to 
prevent  any  binding  or  wedging^  of  the  bar  and  thus  permit  it 
to  fall  freely.  The  object  in  turning  the  bar  at  each  blow  is  to 
make  it  strike  a  fresh  surface  of  rock.  The  hole  is  kept  wet  for 
the  double  purpose  of  preventing  the  heating  of  the  bar  and  soft- 
ening the  rock.  The  chips  and  dust  which  accumulate  in  the 
hole  must  be  removed  frequently  or  else  it  will  form  a  cushion 
which  will  stop  further  cutting  of  the  rock.  Scrapers  are  em- 
ployed for  removing  these  debris.  These  are  iron  rods  \  to 
^  in.  in  diameter,  with  one  end  flattened  and  turned  up  to  form 
a  scoop.  When  being  inserted  in  the  hole  the  scraper  is  turned 
in  the  fingers  so  as  to  take  on  a  load  of  chips  and  dust,  which  is 
then  hoisted  out  of  the  hole  by  withdrawing  the  scraper.  This 
operation  is  repeated  until  all  the  debris  is  cleared  from  the  hole. 
Drilling  by  means  of  bars  is  very  efficient  in  rocks  of  small  tenacity, 
like  sandstones  and 'calcareous  rocks.  In  these  materials  a  man 
working  10  hours  a  day  can  drill  from  5  to  15  lin.  ft.  of  hole: 
for  harder  rocks  the  chisel  or  hand-drill  and  hammer  are  more 
efficient  drilling-tools. 

Chisel  or  Hand-drill. — The  hand-drill  (Fig.  21)  is  an  iron  01 
steel  rod  terminating  at  one  end 
in  a  cutting  edge  and  at  the  other 
end  in  a  flat  face  to  receive  the  blow 
of  the  hammer.  As  in  the  bar-drill 
and  for  the  same  purpose,  the  bit  is 
made  wider  than  the  shank  of  the 
drill,  this  excess  width  varying  with 
the  depth  of  hole  to  be  bored.  FlG'  2L  •  FlG'  22' 

Hammer.— The  hammer  (Fig.  22)  used  with  the  hand-drill 
consists  of  a  parallelopipedon  of  iron  with  steel  ends,  and  an  eye 
at  the  center  to  receive  a  handle.  The  length  of  the  hammer-head 
is  usually  from  6  to  8  ins.,  and  it  has  a  cross-section  from  2J  to 
3  ins.  square.  The  handle  is  usually  about  18  ins.  long.  The 
total  weight  of  the  hammer  is  about  5  Ibs. 

Method   of   Operation. — The  manner   of   operating  the   hand- 


54  EARTH  AND  ROCK  EXCAVATION. 

drill  and  hammer  is  as  follows:  Holding  the  drill  against  the  rock 
and  in  his  left  hand,  the  driller  strikes  its  head  with  the  hammer; 
he  then  raises  and  turns  the  drill  slightly  and  repeats  the  blow. 
This  process  is  continued  until  the  hole  reaches  the  required 
depth.  As  in  bar  drilling,  the  hole  is  kept  wet  and  the  chips  and 
dust  are  removed  at  intervals  with  a  scraper.  This  method  of 
drilling  is  very  slow,  and  should  be  used  only  where  a  few  isolated 
holes  are  to  be  drilled  or  where  an  occasional  boulder  is  encoun- 
tered and  has  to  be  removed  by  blasting.  Where  a  considerable 
number  of  holes  have  to  be  drilled  the  preferable  practice  is  to 
employ  three  men  to  each  drill,  one  man  manipulating  the  drill 
and  the  other  two  striking  it  with  sledges  like  that  already  de- 
scribed but  weighing  only  about  10  Ibs.  and  having  longer  handles. 
The  drills  used  vary  in  length  from  2  to  10  ft.  Usually  the 
men  alternate  in  holding  the  drill,  and  the  blows  are  delivered 
alternately  by  the  two  strikers.  With  expert  workmen  the 
steadiness  and  regularity  of  the  blows  is  quite  remarkable,  the 
click  of  the  hammers  being  as  steady  and  monotonously  regular 
as  the  tick  of  a  clock.  The  progress  of  work  with  hand-drills 
and  hammers  varies  with  the  character  of  the  rock. 

MACHINE-DRILLING. 

The  drilling  of  the  holes  for  blasting  operations  is  more  usually 
performed  by  machine  than  by  hand.  Several  forms  of  rock- 
drilling  machines  or  power  drills  have  been  devised,  but  they 
may  all  be  classed  either  as  percussion  drills  or  rotatory  drills. 
Percussion  drills,  as  their  name  indicates,  operate  by  striking 
a  series  of  sharp  rapid  blows,  while  the  latter  operate  by  a  true 
boring  action  like  a  carpenter's  augur. 

Percussion  Drills. — A  percussion  drill  may  be  described  as  a 
machine  designed  to  operate  a  drill-bar  with  a  reciprocating  motion 
so  that  it  alternately  strikes  and  withdraws  from  a  rock  surface  to 
be  drilled.  The  operating  mechanism  may  be  a  piston  working 
in  a  cylinder  or  it  may  be  any  other  mechanism  capable  of  pro- 
ducing a  reciprocating  motion.  Besides  giving  the  necessary 
reciprocating  motion  the  operating  mechanism  must  gradually 


THE   DRILLING   OF   THE   HOLES. 


55 


rotate  the  drill  so  that  a  fresh  surface  is  always  presented  to  the 
cutting  edge,  and  it  must  also  advance  the  drill  as  the  hole  deepens. 
We  shall  discuss  first  the  piston-driven  form  of  drill,  and  afterwards 
other  forms. 

While  piston  -  driven 
drills  are  usually  operated 
by  compressed  air,  they 
can,  by  slight  modifica- 
tions of  detail,  be  operated 
by  steam.  This  latter  is  the 
power  usually  employed  in 
contract  work  and  open 
excavation.  Compressed 
air  is  preferred  for  mines 
and  underground  quarries, 
and  where  a  large  number 
of  drills  are  supplied  from 
one  plant.  The  term 
"rock-drill  "  is  almost  uni- 
versally adopted  for  drills 
of  piston  type  whether 
air-  or  steam-driven.  The 
various  drills  on  the  mar- 
ket are  practically  identical  in  principle,  and  differ  only  in  con- 
struction details,  valve  actions,  and  the  materials  used.  No 
machine  is  subject  to  more  severe  service,  and  selection  should 
be  based  upon  running  qualities,  cutting  capacity,  and  endurance. 

The  rock-drills  of  the  Ingersoll-Rand  Company  may  be  taken 
as  typical  of  this  class  of  machinery.  They  are  made  in  two 
types,  distinguished  by  the  valve  movements.  Fig.  23  illustrates 
the  Sergeant  "  Auxiliary  Valve  "  drill,  mounted  on  a  tripod.  This 
has  the  usual  drill-cylinder,  sliding  in  a  guide-shell  under  control 
of  a  feed-screw  manipulated  by  a  crank.  The  shell  in  time  is 
mounted  on  the  tripod  saddle.  This  drill  has  an  air-  or  steam- 
thrown  valve  of  spool  type.  Pressure  is  admitted  to  throw  this 
valve  by  a  small  arc-shaped  auxiliary  valve  which  is  struck  and 


FIG.  23. 


56 


EARTH   AND    BOCK   EXCAVATION. 


moved  by  the  piston  in  its  travel.  The  advantage  of  this  valve 
movement  is  that  while  the  main  valve  is  balanced  and  independ- 
ent of  the  piston,  it  is  positively  actuated  whatever  the  stroke. 
The  main  valve  action  is  independent  of  the  condition  of  the 
cylinder-bore  or  the  fit  of  the  piston.  The  stroke  is  variable  from 
a  minimum  of  about  2  inches  up  to  the  maximum  of  the  drill. 
The  blow  struck  is  absolutely  uncushioned,  and  this  drill  is  adapt- 
able to  rock  of  every  degree  of  hardness  and  every  quality  and 
structure. 

Fig.  24  illustrates  the  Rand  " Little  Giant"  drill.    This  is  a 

i  tappet- valve  type,  i.e.,  the  main 

valve  is  mechanically  thrown  by 
a  tappet,  or  rocker,  which  is 
struck  by  the  piston.  The  valve 
in  this  drill  is  balanced  and  free 
from  excessive  wear  due  to  pres- 
sure. This  drill  is  peculiarly 

!  ^_^^B^  effective  where  steam  is  to  be 

used,  especially  if  wet  steam  and 
low  pressure  only  are  available. 
The  manufacturers  claim 
that  an  exclusive  feature  of 
especial  value  in  these  two  drills 
is  the  " release  rotation,"  which 
H'  frees  the  rifle -bar  when  the  steel 
^\  sticks  in  the  hole  and  thus  pre- 
\  vents  broken  rifle-bars,  twisted 
steels,  and  broken  shanks.  An- 
other marked  feature  in  the 
drills  of  this  company  is  their 
perfect  simplicity,  the  absence  of 
complication  laying  them  open  to  injury.  Endurance  is  secured 
by  the  use  of  iron  and  steel  of  extra  quality  and  special  treat- 
ment. 

The  tripod  mounting  is  the  one  usually  employed  in  open 
excavation,  as  quarries,  railway  cuts,  contract  work,  etc.     In  the 


\ 


FIG.  24. 


THE  DRILLING  OF  THE  HOLES. 


57 


mine  and  tunnel  drills,  the  tunnel  column  (vertical)  and  the  shaft- 
bar  (horizontal)  are  the  usual  mptintings. 

The  size  of  a  drill  is  usually  designated  by  its  cylinder  diameter. 
The  makers  in  question  further  use  a  size  letter  which  distinguishes 
the  limits  of  size,  giving  a  certain  flexibility  within  these  limits. 
The  following  table  from  the  Ingersoll-Rand  Company  gives  the 
more  important  data  regarding  their  drills. 


Cylinder. 

Maximum 

Size  Letter. 

Advisable 
Depth  of 
Hole. 

Diameter  of 
Hole. 

Diameter. 

Stroke. 

A 

Inches. 

Inches. 
5 

Feet. 

5 

Inches. 

t-ui 

B 

2| 

6 

9 

These  s  zes  are  for  com- 

C 

2| 

6* 

10 

l|-2±  i 

mon  use  in  mine,  tunnel, 

D 
E 

3 
8J 

14 
16 

{i~|t  I 

quarry,  aud  open-cut  ex- 
cavation. 

F 

8i 

7 

20 

lf-3?J 

^ 

These  sizes  are  for  the 

G 

4£ 

9 

27 

3  -6    ) 

heaviest  work  in  contracts 

H 

5-5$ 

8 

32 

3  -6    f 

and  .submarine    excava- 

tion. 

The  efficiency  of  the  air-drill  varies  with  the  character  of  the 
rock.  Manufacturers  generally  state  that  the  average  work 
per  ten-hour  day  drilling  holes  downward  and  including  the  time 
lost  in  setting  up  the  drill  and  changing  the  bits  may  be  assumed 
to  be  from  50  to  75  ft.  of  hole.  The  writer,  however,  kept 
records  for  nearly  six  months  of  the  daily  work  performed  by 
ten  air-drills  working  on  the  mica-schist  rock  of  New  York  City, 
which  is  much  softer  than  granite,  and  found  the  average  ten- 
hour  day's  work  to  be  45  ft.  On  one  occasion  a  drill  made  72  ft., 
but  this  was  an  exceptional  instance  and  was  the  maximum 
record  made  by  any  of  the  ten  drills  observed.  The  horse-power 
required  to  operate  an  air-drill  is  from  8  to  10  H.P.  per  hour, 
according  to  the  size  of  the  drill,  and  consequently  a  portable 
steam-boiler  cannot  operate  more  than  four  drills. 

A  blacksmith-shop  is  a  necessary  adjunct  to  a  plant  of  air- 


58  EAETH  AND  ROCK  EXCAVATION. 

drills,  as  the  bits  have  to  be  frequently  sharpened,  especially 
when  the  work  is  in  granitic  or  feldsparitic  rock.  A  blacksmith 
with  a  boy  helper  can  sharpen  the  bits  for  four  drills.  Each  drill 
is  operated  by  two  men,  and  its  running  expenses  are  composed 
of  the  following  items: 

One-fourth  of  the  daily  expense  of  the  boiler,  fireman  in- 
cluded   $2.20 

One-fourth  the  blacksmith-shop  expenses 1 . 30 

Two  operators,  at  $2  per  day  each 4 . 00 

Total  expense -. $7 . 50 

This  sum  divided  by  the  number  of  feet  drilled  per  day  gives 
the  cost  per  lineal  foot  drilled.  This,  in  the  case  previously  men- 
tioned as  recorded  by  the  author,  where  the  drills  averaged  45  ft. 

7  5 
per  day,  was  —-  =  .166  per  foot.    To  this  must  be  added  the 

maintenance,  interest  on  investment,  and  sinking  fund. 

The  preceding  remarks  have  referred  to  piston-drills  operated 
by  steam  or  compressed  air.  Recently  electrically  operated  per- 
cussion-drills have  been  put  on  the  market  and  are  considerably 
employed  in  some  Western  mines.  The  general  appearance  of 
these  electric  drills  is  much  the  same  as  that  of  air-drills,  and  in 
fact  air-drill  standards  are  followed  in  all  possible  features.  Sev- 
eral manufacturers  are  already  turning  out  electric  drills,  all  of 
which  are  constructed  on  the  same  principle.  The  following  is  a 
description  of  the  Durkee  electric  drill,  taken  from  the  Engineering 
News: 

The  Durkee  drill  here  illustrated  (Fig.  25)  is  operated  by  a 
flexible  shaft,  which  is  in  effect  several  coil  springs  wound  in  oppo- 
site direction,  one  over  the  other.  This  shaft  is  driven  by  a 
portable  electric  motor  of  1J  H.P.  The  shaft  is  attached  to  a 
bevel-gear  driving  a  crank-shaft,  A,  which  passes  through  the 
drill-casing.  The  crank-pin  works  in  the  slotted  horizontal  arm 
of  the  bell-crank  lever,  which  is  mounted  on  a  shaft  journaled 


THE    DRILLING    OF    THE    HOLES.  £9 

in  the  casing.  The  vertical  arm  straddles  the  drill-rod  and  is 
fitted  to  trunnions  on  a  casting>  which  slides  on  the  rod.  Between 
this  casting  and  collars  on  the^rod  are  coiled  springs  through 
which  the  power  is  transmitted  for  movement  of  the  rod  in  each 
direction.  The  parts  are  so  proportioned  as  to  give  a  sharp 


•A. 


FIG    25. 

cutting  stroke  and  a  slower  return  stroke,  while  a  flywheel, 
on  the  crank-shaft  also  provides  for  uniformity  of  action.  At 
the  heel  of  the  rod  is  a  rifled  section,  or  ratcheted  rod,  working 
in  a  rifted  nut  by  which  the  required  rotary  movement  is  given 
to.  the  drill-bit.  The  rotating  device  and  the  chuck  are  the  same 


60 


EARTH  AND    ROCK    EXCAVATION. 


as  in  compressed-air  drills  of  the  ordinary  type.  The  cylindrical 
casing  is  fitted  to  a  slide  or  feed-table  operated  by  a  feed-screw 
and  crank-handle  in  the  usual  way,  and  this  table  is  mounted 
either  upon  a  column,  tripod,  or  bar,  according  to  the  require- 
ments of  the  work.  The  machine  makes  about  580  strokes  per 
minute,  and  its  weight,  exclusive  of  the  tripod  or  other  support, 
is  about  230  Ibs.  A  number  of  machines  are  now  in  use  in  mining 
operations,  and  they  are  introduced  by  the  Mine  and  Smelter 
Supply  Company  of  Denver,  Col. 

The  Marvin  Electric  Drill  Company  of  Binghamton,  N.  Y., 
manufacture  a  percussion  drill  depending  for  its  operation  upon 
the  well-known  solenoid  principle.  Referring  to  cross-section  of 
the  drill  (Fig.  25a),  the  part  marked  3  is  a  double  solenoid  inside  of 


FIG.  25a. 

which  the  active  part,  corresponding  to  the  piston  of  an  air-drill, 
is  free  to  move.  A  special  current  is  supplied  to  this  double  sole- 
noid in  such  a  manner  as  to  cause  this  working  part  to  reciprocate. 
The  drill  is  mounted  on  a  tripod,  and  it  differs  very  little  in  appear- 
ance from  an  ordinary  air-drill.  The  absence  of  motor,  rheostats, 
starting-box,  cranks,  shafts,  gears,  cams,  packed  joints,  close  fits, 
stuffing-boxes,  and  exhausts  is  always  appreciated  in  coming  in 
contact  with  this  machine.  It  has  been  on  the  market  for  some 
time,  and  is  now  offered  in  three  sizes  for  holes  down  to  4',  8',  and 
16'  respectively. 

Rotary  Drills.  —  Rotary  drilling-machines  are  very  seldom 
employed  in  ordinary  excavations,  although  they  are  extensively 
used  in  tunneling  and  prospecting,  and  consequently  their  use 


THE    DRILLING   OF    THE    HOLES.  61 

among  contractors  is  very  limited.  Rotary  drills,  as  the  name 
indicates,  bore  holes  by  rotation ;  *  that  is,  a  core  of  rock  is  cut  out 
by  a  hollow  cylinder  provided  with  a  cutting  edge  having  a  rapid 
rotary  movement  and  pressed  with  great  force  against  the  rock. 
On  this  principle  two  kinds  of  machines  are  built,  diamond  drills 
and  those  with  hardened  steel  bits. 

Diamond  drills  consist  of  a  hollow  bit  on  the  cutting  edge 
of  which  there  are  diamonds  set  in  such  a 
manner  that  they  are  the  only  part  of  the 
tool  coming  in  contact  with  the  rock  (Fig. 
26).  An  essential  feature  of  these  machines 
is  a  stream  of  water  forced  through  the  in- 
terior of  the  bit  for  the  double  purpose  of 
keeping  the  bit  cool  and  the  hole  clear  of 

sediment,  which  is  forced  out  by  the  pressure  of  the  water. 
Diamond  drills  bore  perfectly  straight,  smooth  holes  to  any  depth 
or  in  any  direction  from  vertical  to  horizontal,  bringing  to  the 
surface  a  solid  section  or  core  of  all  strata  passed  through,  show- 
ing their  exact  depth,  thickness,  and  the  character  of  the  rock. 
For  these  reasons  they  are  commonly  employed  in  prospecting 
and  for  geological  purposes;  but  they  could  be  also  employed 
with  great  advantage  by  engineers  and  contractors  before  under- 
taking rock  excavation,  of  importance  in  order  to  determine 
both  the  nature  of  the  soil  and  the  thickness  and  direction  of 
the  strata  to  be  met  with.  In  such  cases  the  hand  diamond  drill 
capable  of  boring  1^-inch  holes  and  taking  out  1-inch  cores,  will 
be  found  very  useful. 

The  machine  is  mounted  on  hollow  standards,  with  hollow 
back  braces,  thus  combining  strength,  rigidity,  and  light  weight. 
Two  cranks,  one  on  each  side  of  the  standard,  moved  by  hand 
and  engaging  a  system  of  cog-wheels,  impart  a  rapid  rotary  move- 
ment to  the  shaft  and  consequently  to  the  bit.  The  pump  fur- 
nished with  this  machine  is  mounted  on  one  of  the  columns  as 
shown  in  the  cut,  and  is  worked  by  an  eccentric  on  the  main  crank- 
shaft. The  lifting  apparatus  is  mounted  on  the  back  braces. 
It  consists  of  a  drum  wound  with  wire  rope,  and  the  rods  are 


62 


EARTH    AND    ROCK    EXCAVATION. 


FIG.  27. 


raised  by  hand-power  with  rope  and  blocks.     With  this  simple 
machine  holes  can  be  bored  to  a  depth  of  300  ft.,  and  it  is  operated 

by  only  two  men,  who  may  trans- 
fer it  where  required,  since  the 
total  weight  of  the  machine  is 
only  190  Ibs.  Fig.  27  shows  a 
small  Rotary  Diamond  Drill  oper- 
ated by  steam  as  constructed  by 
the  Sullivan  Company  of  Chicago. 
Owing  to  the  great  rise  in  the 
price  of  diamonds,  the  cost  of 
extracting  cores  by  the  diamond 
drills  has  recently  been  greatly 
increased,  and  consequently  re- 
source was  had  to  a  new  drill 
provided  with  a  hardened  steel 
bit.  It  was  invented  by  Mr.  F. 
Harley  Davis,  an  Australian  engineer,  and  introduced  in  the 
United  States  by  the  Davis  Calix  Drill  Company  of  New  York 
City. 

This  machine,   both  in   general   appearance    and  manner  of 
working,  is  similar  to  the  diamond  drilling-machine, 
with  the  difference  that  the    cutting,  instead  of 
being  done  by  diamonds,  is  performed  by  means 
of  steel  teeth  of  special  construction,  as  indicated 
by  Fig.  28.      The  teeth   are  2|  ins.  long,  T\  in. 
thick,  and  1J  ins.  wide;  they  are  straight  on  the 
cutting  edge,  with  the  back  at  an  angle  of  30°  or 
35°;  between  each  tooth  there  is  a  groove.     When 
the  teeth  wear  down  to  a  length  of  2  ins.  they  need  The  Davjg  Cutter. 
to  be   recut.     The   Davis  cutter  has  a  sort   of         j^G  2§ 
hammer  and  chisel  action,  cutting  the  rock  into 
;small  chips.     A  peculiar  feature  of  this  drill  is  the  calix,  shown 
in   Fig.   29,  whose    office  is   to   receive   the  chips   of   the   rock 
and   hold   them   until   they   are   removed   with   the   core.     The 
-ordinary  method  of  operating  the  drill  is  very  simple.     Power  is 


THE   DRILLING    OF   THE    HOLES.  63 

received  through  a  horizontal  shaft  and  is  delivered  by  bevel- 
wheels  to  a  horizontal  wheel  which  grips  the  drill-rod  by  suitable 
mechanism.  Water  is  iurnisherf*  to  the  drill-rod  from  a  pump  by 
means  of  a  hose.  A  hook  inserted  at  the  top  of  the  drill-rod  is 
for  the  purpose  of  hoisting  the  drill-rod,  with  its  attached  cutter 
and  calix,  together  with  the  core  of  rock  from  the  bore. 

The  Davis  cutter,  although  it  cuts  almost  any  kind  of  rock,  is 
very  efficient  for  boring  through  sandstones,  hard  shales,  and 
similar  soft  rocks.  These  have  been  penetrated  at  the  rate 
of  J  in.  per  revolution  of  the  cutter.  The  drill  is  manufactured 
in  different  sizes,  capable  of  taking  out  cores  from  2f  to  10J  ins. 
in  diameter.  In  New  York  a  core  of  10  ins.  in  diameter  was 


CORE  BARREL'  REDUCING  PLUG 

FIG.  29. 


taken  from  a  bore-hole  11J  ins.  in  diameter,  drilled  for  the  Stokes 
Apartment  Hotel  at  Seventy-fourth  Street  and  Broadway. 

Rotary  drills  have  not  so  far  found  general  employment  on 
public  works;  an  exception,  however,  should  be  made  for-  the 
Brandt's  hydraulic  drilling-machine,  which  has  been  somewhat 
extensively  used  in  the  more  recently  excavated  Alpine  tunnels 
of  Continental  Europe.  The  Brandt  hydraulic  machine  was 
invented  by  Mr.  A.  Brandt,  and  it  was  employed  for  the  first 
time  in  the  excavation  of  the  Sonnenstein  tunnel  along  the  Gemiin- 
den-Ebensee  R.  R.  in  the  *year  1877.  The  Brandt  machinq  re- 
ceived a  fair  test  in  the  Pfaffensprung  tunnel  of  the  St.  Gothard 
R.  R.,  and  since  then  it  was  employed  as  a  substitute  for  the 
percussion  drilling-machine  in  the  Arlberg  and  Brandleite  tunnels, 
and  it  is  now  the  only  drilling-machine  used  in  the  excavation 
of  the  Simplon  tunnel. 

The  Brandt  machine  consists  of  a  four-wheeled  carriage  sup- 
porting at  the  center  a  beam  provided  with  two  arms  of  different 


64 


EARTH    AND    ROCK    EXCAVATION. 


length;  the  short  arm  carries  the  boring  mechanism,  while  the 
longer  one  is  provided  with  a  counterpoise.  The  distributor  is 
located  near  the  center  of  the  beam.  The  short  arm  is  furnished 
with  a  clamp  holding  the  butting  column,  which  is  a  wrought-iron 
cylinder  with  a  plunger  constituting  a  ram,  and  is  jammed  by 
hydraulic  pressure  between  the  walls  of  the  heading  of  the  tunnel, 
thus  forming  a  rigid  support  for  the  boring-machine  and  an  effi- 
cient abutment  against  the  reaction  of  the  drill.  This  butting 
column  can  be  rotated  on  its  clamp  in  a  plane  parallel  to  the  axis 
of  the  beam.  Three  or  four  separate  boring-machines  can  be 
mounted  on  the  column  and  can  be  adjusted  in  any  reasonable 
position. 

The  boring-machine  performs  the  double  function  of  continually 
pressing  the  drill  into  the  rock  by  means  of  a  hollow  ram  (1)  and 
of  imparting  to  the  drill  and  ram  a  uniform  rotary  motion.  This 


lie.  30. 

rotary  motion  is  given  by  a  twin-cylinder  single-acting  hydraulic 
motor  (E),  the  two  pistons,  of  2}  ins.  stroke,  acting  reciprocally 
as  valves.  The  cranks  are  fixed  at  an  angle  of  90°  to  each  other 
on  the  shaft,  which  carries  a  worm,  gearing  with  a  worm-wheel 
(Q)  mounted  upon  the  shell  (R)  of  the  hollow  ram  (1),  and  this 
shell  in  turn  engages  the  ram  by  a  long  feather,  leaving  it  free 
to  slide  axially  to  or  from  the  face  of  the  rock.  The  average 
speed  of  the  motor  is  150  to  200  revolutions  per  minute. 
The  loss  of  power  between  the  worm  and  worm-wheel  is  only  15 


THE    DRILLING    OF    THE    HOLES.  65 

per  cent,  at  the  most;  the  worm  being  of  hardened  steel  and  the 
wheel  of  gun-metal,  the  two  surfaces  in  contact  acquire  a  high 
degree  of  polish,  resulting  iri  little  wearing  or  heating.  Taking 
into  consideration  all  other  sources  of  loss,  70  per  cent,  of  the  total 
power  is  utilized.  The  pressure  on  the  drill  is  exerted  by  a  cylin- 
der and  hollow  ram  (7)  which .  revolves  about  the  differential 
piston  S,  which  is  fixed  to  the  envelope  holding  the  shell  R.  This 
envelope  is  rigidly  connected  to  the  bed-plate  of  the  motor,  and 
by  means  of  the  vertical  hinge  and  pin  T  is  held  by  the  clamp 
V  embracing  the  butting  column.  When  water  is  admitted  to 
the  space  in  front  of  the  differential  piston  the  ram  carrying 
the  drilling-tool  is  thrust  forward,  and  when  admitted  to  the 
annular  space  behind  the  piston,  the  ram  recedes,  withdrawing 
the  tool  from  the  blast-hole.  The  drill  proper  is  a  hollow  tube 
of  tough  steel  2J  ins.  in  external  diameter,  armed  with  three  or 
four  sharp  and  hardened  teeth,  and  makes  from  5  to  10  revolutions 
per  minute,  according  to  the  nature  of  the  rock.  When  the  ram 
has  reached  the  end  of  the  stroke  of  2  ft.  2J  ins.,  the  tool  is  quickly 
withdrawn  from  the  hole  and  unscrewed  from  the  ram;  an  ex- 
tension rod  is  then  screwed  into  the  hole  and  into  the  ram,  and 
the  boring  is  continued,  additional  lengths  being  added  as  the 
tool  grinds  forward ;  each  change  of  tool  or  rod  takes  about  fifteen 
to  twenty-five  seconds  to  perform.  The  extension  rods  are  forged 
steel  tubes  fitted  with  four-threaded  screws,  and  having  the  same 
external  diameter  as  the  drill.  They  are  made  in  standard  lengths 
of  2  ft.  8  ins.,  1  ft.  10  ins.,  and  llf  ins.  The  total  weight  of  the 
drilling-machine  is  264  Ibs.,  and  that  of  the  butting  column 
when  full  of  water  is  308  Ibs.  The  -exhaust-water  from  the  two 
motor  cylinders  escapes  through  a  tube  in  the  center  of  the  ram 
and  along  the  bore  of  the  extension  rods  and  drill,  thereby  scouring 
away  the  debris  and  keeping  the  drill  cool;  any  superfluous  water 
finds  an  exit  through  a  hose  below  the  motor  and  thence  away 
down  the  heading.  The  area  of  the  piston  for  advancing  the 
tool  is  15J  sq.  ins.,  which,  under  a  pressure  of  1470  Ibs.  per  square 
inch,  gives  a  pressure  of  over  10  tons  on  the  tool,  while  for  with- 
drawing the  tool  2J  tons  is  available. 


66 


EARTH  AND   ROCK   EXCAVATION-. 


In  the  gneiss  rock  found  at  Isella  on  the  Simplon  Tunnel,  a 
hole  2f  ins.  in  diameter  and  3  ft.  3  ins.  in  length  is  drilled  normally 
in  twelve  minutes  to  twenty-five  minutes.  The  time  taken  to 
drill  ten  to  twelve  holes  4  ft.  7  ins.  deep  is  two  and  one-half  hours. 

By  means  of  this  machine  a 
daily  advance  of  18  to  19  ft. 
6  ins.  is  made  in  a  heading 
having  a  minimum  cross- 
section  of  59  sq.  ft. 

Still  another  machine 
has  been  lately  introduced 
in  public  works  for  drilling 
holes  of  larger  dimensions, 
chiefly  used  to  prepare  for 
the  blasting  of  loose  soils 
where  large  quantities  of  ex- 
plosive of  the  lowest  effi- 
ciency are  required .  The  ma- 
chine, of  the  percussion  type, 
can  be  compared  to  a  very 
heavy  churn-drill,  lifted  by 
steam-power,  and  striking 
the  soil  by  its  own  weight. 
The  drill  is  made  up  of  dif- 
ferent parts,  as  the  bit,  the 
drill-stem,  and  the  rope- 
socket,  screwed  together  so 
as  to  form  a  solid  bar  of  steel 
over  300  Ibs.  in  weight.  The 
machine  is  mounted  on  a 
truck  provided  with  a  boiler  and  an  engine.  An  A  frame  mounted 
at  the  rear  end  of  the  truck  carries  on  top  a  sheave  over  which 
passes  the  Manila  rope.  The  drill  is  lifted  by  winding  the  rope 
around  the  drum  of  the  engine,  and  then  it  is  released  all  at  once  so 
that  it  will  strike  the  ground  with  great  force,  descending  rapidly  on 
account  of  its  weight.  Fig.  30a  indicates  one  of  these  machines  as 
built  by  the  Keystone  Driller  Company  of  Beaver  Falls,  Pa. 


FIG.  30a. 


3 

I 


CHAPTER  VI. 

ROCK  EXCAVATION  BY  BLASTING;    EXPLOSIVES  AND  THEIR 
TRANSPORTATION  AND  STORAGE. 

IN  the  excavation  of  rocks  by  blasting  the  operation  which 
follows  the  drilling  is  the  filling  of  the  drilled  holes  with  the 
blasting  charge.  This  consists  of  an  explosive  substance,  which 
is  a  chemical  compound  of  such  composition  that  when  ignited 
it  undergoes  a  sudden  transformation  into  gas  occupying  many 
times  the  space  of  the  original  compound.  The  most  important 
substances  employed  as  explosives  are  gunpowder,  nitroglycerine, 
and  dynamite. 

Gunpowder. — Gunpowder  was  discovered  in  Germany  about 
the  year  1320  by  Berthold  Schwartz,  a  monk  of  the  order  of 
St.  Augustine.  In  reading  the  magnificent  synopsis  of  the  history 
of  explosives  given  by  Drinker  in  his  work  on  tunneling,  it  seems 
that  gunpowder  was  known  long  before  the  generally  accepted 
data  of  its  discovery  by  Schwartz.  There  is  no  doubt,  however, 
that  it  was  only  after  his  time  that  gunpowder  came  into  practical 
use  and  was  a  substance  well  known  to  the  scientific  world.  It 
is  composed  of  charcoal,  sulphur,  and  saltpeter  in  different  pro- 
portions according  to  the  use  it  is  intended  for;  thus  for  mining 
purposes  its  composition  is  as  follows:  65  per  cent,  saltpeter,  15  per 
cent,  sulphur,  and  20  per  cent,  charcoal.  It  is  a  black  granulated 
substance  and  when  ignited  burns,  developing  gases  amounting 
to  280  times  its  former  volume.  Gunpowder  is  ignited  by  the 
application  of  any  substance  heated  to  redness;  flame  alone  will 
not  so  readily  ignite  it. 

The  nature  of  the  gases  developed  by  gunpowder  have  not 
yet  been  ascertained.  It  is,  however,  generally  admitted  that 

67 


68  EARTH  AND  ROCK  EXCAVATION. 

the  oxygen  of  the  saltpeter  converts  nearly  all  the  carbon  of  the 
charcoal  into  carbonic  acid,  C02,  a  portion  of  which  combines 
with  the  potash  of  the  niter  to  form  carbonate  of  potash 
(K2OC02),  the  remainder  existing  in  the  state  of  gas.  The  sul- 
phur is  converted  into  sulphuric  acid  (S03)  and  forms  sulphate 
of  potash,  which  by  reaction  is  decomposed  into  the  hyposulphate 
and  sulphide.  The  nitrogen  of  the  saltpeter  is  almost  entirely 
evolved  in  the  free  state,  and  the  carbon  not  burnt  into  carbonic 
acid  remains  and  forms  oxide  of  carbon,  which  always  accom- 
panies the  explosion  of  gunpowder. 

The  force  of  the  gases  produced  by  the  ignition  of  gunpowder 
has  been  variously  estimated  ,at  from  15,000  to  200,000  Ibs.  per 
sq.  in.  A  discussion  of  this  question  is  given  by  Mr.  Lohr  in 
the  article  "  Explosives  "  in  the  Sports  Engineering  Encyclopedia. 
The  experiments  of  Nobel  and  Able,  Mr.  Lohr  says,  have  sho\vn 
that  the  explosion  of  gunpowder  produces  about  57  per  cent, 
by  weight  of  solid  matters  and  43  per  cent,  of  permanent  gases. 
The  solid  matters  are,  at  the  moment  of  the  explosion,  in  the  fluid 
state.  When  in  this  state  they  occupy  0.6  of  the  space  originally 
filled  by  gunpowder;  consequently  the  gases  occupy  only  0.4  of 
that  space.  These  gases  would  at  atmospheric  pressure  and 
32°  F.  temperature  occupy  a  space  280  times  that  filled  by  powder. 
As  they  are  compressed  into  0.4  of  that  space,  this  would  give 

280 
a  pressure  TrrX  15  =  10,500  Ibs.,  or  about  4.68  tons  per  square 

inch.  But  a  great  quantity  of  heat  is  liberated  in  the  reaction  and 
this  heat  will  enormously  increase  the  tension  of  the  gases.  The 
experiments  of  Nobel  and  Able  showed  that  the  temperature 
of  the  gases  at  the  instant  of  the  explosion  is  about  4000°  F. 
Thus  the  temperature  of  32°  +  461°.2=493°.2  absolute  has  been 

4000 
raised   ,OQ  0=8.11  times,  so  that  the  total  pressure  of  the  gases 


will  be  4.68X8.11=37.9  to  the  square  inch.  That  the  pressure 
of  37.9  tons  to  the  square  inch  is  not  exaggerated  is  shown  by  the 
fact  that  there  are  experiments  indicating  that  the  pressure  of 
the  gases  was  as  high  as  42  tons  to  the  square  inch. 


BLASTING — EXPLOSIVES.  69 

Nitroglycerine. — A  more  modern  explosive  used  as  a  sub- 
stitute of  gunpowder  in  the  excavation  of  rock  is  nitroglycerine, 
discovered  by  Sobrero  in  trfe  year  1847.  Nitroglycerine  is 
obtained  either  by  the  action  of  concentrated  nitric  acid  on 
glycerine,  or  by  a  mixture  of  nitric  acid  at  40°  and  sulphuric 
acid  at  66°,  on  glycerine.  Its  reaction  can  be  represented  by 
the  formula, 

C3H  A+3HN03  -CVH.O,.(NO,).+3HA 

glycerine          nitric  acid          nitroglycerine         water 

The  sulphuric  acid  which  is  mixed  with  the  nitric  does  not  enter 
into  the  reaction,  but  absorbs  the  water  which  is  set  free. 
Nitroglycerine  is  a  clear  yellow,  oily  liquid  with  a  sweet  taste 
but  no  odor;  it  is  poisonous  when  inhaled  or  simply  introduced 
into  the  body  through  the  pores,  producing  headache  and  sick- 
ness. Its  specific  gravity  is  1.595.  Nitroglycerine  burns  very 
quietly  in  contact  with  ignited  bodies,  but  it  explodes  at  a  tem- 
perature of  388°  F.  Its  explosion  is  caused  by  the  slightest 
percussion,  and  this  makes  its  handling  very  dangerous.  Nitro- 
glycerine freezes  at  41°  F.,  and  although  it  explodes  very  easily 
by  percussion  in  its  normal  state,  it  explodes  with  great  difficulty 
when  frozen;  hence  in  America,  at  the  beginning  of  its  use,  nitro- 
glycerine, as  well  as  all  the  other  explosives  containing  it,  were 
transported  only  in  a  frozen  state.  When  nitroglycerine  con- 
tains some  impurities  or  is  not  well  washed  off,  it  undergoes 
spontaneous  decomposition,  accompanied  by  development  of  gases 
and  increase  of  temperature,  which,  in  reaching  388°  F.,  causes 
its  explosion. 

There  are  no  complete  experiments  upon  the  pressure  of  the 
gases  generated  in  the  explosion  of  nitroglycerine.  Mr.  Nobel 
estimates  the  strength  of  nitroglycerine  as  4  times  that  of 
gunpowder — and  the  relative  strength,  bulk  for  bulk,  since  the 
specific  gravity  of  gunpowder  is  1  and  nitroglycerine  1.6,  as  5.91 
times  that  of  gunpowder.  This  is  a  very  important  feature  in 
rock  excavation,  because  with  a  given  height  of  charge  in  a  bore- 
hole, nitroglycerine  exerts  about  5J  times  the  force  of  gunpowder. 


70  EARTH  AND  ROCK  EXCAVATION. 

Notwithstanding  its  enormous  strength  nitroglycerine  is  never- 
employed  in  its  liquid  state  for  rock  excavation,  but  is  always 
mixed  with  some  other  substance  which  renders  its  handling  less 
dangerous. 

Dynamite. — Any  mixture  of  nitroglycerine  with  an  absorbent 
substance  which  reduces  it  into  a  solid  mass  is  called  dynamite. 
It  is  on  account  of  this  simple  transformation  that  the  explosives 
containing  nitroglycerine  have  been  so  extensively  used  in  prac- 
tical works.  In  regard  to  the  nature  of  the  absorbent  substance, 
dynamite  is  divided  into  two  classes — true  and  false  dynamite. 

Dynamite  was  discovered  in  1865  by  Prof.  Nobel.  He  mixed 
nitroglycerine  with  a  siliceous  sand  called  kieselguhr,  found  at 
Oberlohe  near  Unterlau,  Hanover.  It  is  a  white,  siliceous,  soluble 
substance,  composed  of  microscopic  shells  of  diatoms,  which  are 
endowed  with  great  strength  and  an  enormous  power  of  absorp- 
tion of  liquid  in  proportion  to  their  size;  they  will  absorb  75  per 
cent,  of  nitroglycerine.  In  being  absorbed,  nitroglycerine  does 
not  undergo  any  chemical  change;  it  burns,  freezes,  and  explodes- 
under  the  same  conditions  as  in  the  fluid  state.  Dynamite  is  easily 
handled  and  transported  without  danger,  but  explodes  with  more 
difficulty  by  percussion. 

During  the  explosion  of  the  nitroglycerine  contained  in 
dynamite  some  oxygen  is  set  free,  and  in  order  to  utilize  it,  it 
seems  logical  to  use  as  an  absorbent  matter  able  to  burn  at  the 
moment  of  the  explosion,  thus  increasing  both  the  quantity  of 
gases  and  the  heat  produced,  and  consequently  increasing  also 
the  efficiency  of  the  dynamite.  Under  the  general  name  of  false 
dynam  te  are  included  all  the  various  nitroglycerine  explosives 
in  which  the  absorbent  substances,  instead  of  remaining  inert 
during  the  explosion,  liberate  gases,  thus  greatly  increasing  the 
efficiency  of  the  dynamite.  When  the  new  substance  introduced 
into  the  composition  of  dynamite  is  able  to  generate  a  large 
volume  of  gases,  compounds  of  greater  efficiency  are  obtained. 

Nearly  all  the  explosives  with  fancy  names  which  are  p^ced 
on  the  market  by  different  manufacturers  are  simply  false  dyna- 
mites. Thus,  for  instance,  the  Lithofacter  manufactured  by 


BLASTING — EXPLOSIVES.  71 

Krebs  at  Cologne  is  composed  of  52  parts  of  nitroglycerine,  30  of 
fine  sand,  12  of  charcoal,  4  of  nitrate  of  potash,  and  2  of  sulphur. 
In  a  word,  he  uses  gunpowdei^as  an  absorbent,  and  the  sand  to 
give  weight  to  the  compound.  The  Forsyte  dynamite  which 
has  been  so  extensively  used  in  the  rock  excavation  for  the  New 
York  Subway  is  a  false  dynamite  composed  of  nitroglycerine, 
sawdust,  and  nitrate  of  soda,  and  a  little  white  of  lead  for  weight. 
Nearly  all  manufacturers  of  explosives  make  a  secret  of  the 
ingredients  entering  into  the  composition  of  their  products.  To 
make  a  secret  of  the  ingredients,  even  if  it  be  necessary  for  com- 
mercial purposes,  does  not  speak  well  of  the  product,  and  engineers 
and  contractors  should  always  refuse  to  buy  products  that  they 
do  not  thoroughly  know,  especially  when  the  work  is  to  be  done 
in  a  close  space,  as  in  tunnels  and  mines.  It  has  been  already 
remarked  that  the  nitroglycerine  produces  a  poisonous  effect 
upon  men ;  but  the  gases  generated  by  its  explosion  are  not  poison- 
ous but  simply  asphyxiating.  It  is,  however,  impossible  to  know 
the  effects  of  the  gases  produced  by  the  other  substances  intro- 
duced if  these  are  not  known.  Doctors  have  noticed  the  poisonous 
effects  of  nitroglycerine  upon  the  men  working  in  the  Croton 
Aqueduct  tunnel.  In  an  article  published  in  the  Scientific 
American  Supplement  it  is  stated  that  since  were  found  the  men 
working  in  the  tunnel  affected  by  the  same  symptoms  as  those 
produced  by  pure  nitroglycerine,  the  cause  must  be  that,  mixed 
with  the  gases  produced  in  the  explosion,  there  are  unexploded 
particles  of  nitroglycerine  in  a  volatile  state,  and  these  particles 
inhaled  by  miners  affected  their  health.  If  the  doctor's  conclu- 
sions are  true  it  means  that  only  part  of  the  nitroglycerine  ex- 
ploded, and  consequently  only  part  of  its  force  was  utilized ;  hence 
the  explosive  was  not  very  efficient;  or  else  the  poisonous  effect 
was  due  to  the  presence  of  gases  generated  by  unknown  sub- 
stances which  produced  the  same  symptoms  as  the  inhalation  of 
nitroglycerine.  In  any  case  such  an  explosive  should  be  dis- 
carded by  the  contractors,  because  either  it  is  not  efficient,  or  by 
affecting  the  men,  they  will  work  under  abnormal  conditions  and 
their  work  will  be  dearer  in  the  end. 


72  EARTH  AND  ROCK  EXCAVATION. 

The  explosive  power  of  dynamite  has  not  yet  been  correctly 
determined.  In  the  few  experiments  made  for  calculating  the 
force  of  various  explosives,  the  force  of  gunpowder  is  taken  as 
unity.  Mr.  Nobel  tried  to  compare  the  force  of  the  various  explo- 
sives by  loading  a  mortar  with  a  32-lb.  shot  and  calculating  the 
distance  of  the  shot,  the  mortar  being  inclined  at  an  angle  of  10°. 
Weight  for  weight  he  deduced  the  comparative  forces  of  the  vari- 
ous explosives  as  follows:  Gunpowder,  1;  dynamite,  2.89;  nitro- 
glycerine, 4.  Comparing  these  explosives  bulk  for  bulk,  the 
specific  gravity  of  dynamite  being  1.65  of  the  gunpowder,  they 
range  as  follows:  Gunpowder,  1;  dynamite,  4.23;  nitroglyc- 
erine, 5.71.  These  figures  mean  that  1  Ib.  of  dynamite  will  pro- 
duce a  force  4J  times  greater  than  that  produced  by  1  Ib.  of  gun- 
powder. • 

In  artillery  the  force  of  the  various  explosives  is  usually  cal- 
culated by  a  specially  constructed  gun  in  which,  close  to  the  charge, 
there  is  a  bell  of  the  same  metal  forged  with  the  gun.  The  bell 
is  filled  in  with  a  plug  of  lead  or  other  soft  metal.  In  the  explo- 
sion, the  gases  will  compress  the  lead,  and  by  measuring  the  plug 
before  and  after  the  explosion  it  is  known  how  much  it  was  com- 
pressed. By  placing  a  similar  plug  of  lead  in  a  testing- machine 
the  force  required  to  compress  it  an  equal  amount  is  determined 
and  from  this  is  deduced  the  force  per  unit  of  surface  exerted  by 
the  gases  during  the  explosion. 

TRANSPORTATION   AND   STORAGE    OF   EXPLOSIVES. 

In  Continental  Europe,  on  account  of  the  constant  fear  of 
political  rebellions  and  anarchist  attacks  on  persons  and  property, 
the  manufacturing,  storing,  transporting,  and  sale  of  explosives 
are  regulated  by  special  and  strict  laws  and  are  under  the  rigid 
surveillance  of  the  government.  In  the  United  States  anybody 
is  free  to  manufacture  explosives  after  obtaining  a  special  per- 
mission from  the  State,  which  is  given  upon  guarantee  that  in 
case  of  explosion  no  serious  damage  will  result  to  persons  and 
property  outside  the  factory.  For  this  reason  factories  are 


BLA.STING — EXPLOSIVES.  73 

located  in  the  open  country  and  in  some  isolated  spot  far  from 
towns  and  villages  or  even  farni-houses.* 

Transporation  of  Explosives.^-The  laws  regulating  the  trans- 
portation of  the  explosives  on  European  railroads  tend  to 
detect  the  existence  of  any  clandestine  factory  and  to  avoid 
as  much  as  possible  the  causes  of  explosion,  thus  reducing  the 
danger  to  persons  and  property.  The  detection  of  the  unau- 
thorized factories  is  obtained  from  the  fact  that  no  explosive 
can  be  shipped  on  any  railroad  or  vessel  if  it  is  not  produced  by 
a  national  factory  working  under  the  government  permission. 
In  case  the  explosive  to  be  transported  was  produced  in  a  foreign 
country,  it  must  be  accompanied  by  a  special  permission  of  the 
national  government,  which  is  given  only  in  case  that  the 
factory  was  duly  authorized  and  is  working  under  the  surveillance 
of  the  foreign  government  in  whose  jurisdiction  the  factory  is 
located.  The  explosives  must  be  packed  according  to  a  pre- 
scribed manner  and  the  boxes  must  have  on  the  cover  a  de- 
tailed description  of  the  contents,  the  weight  of  the  explo- 
sives, the  name  of  the  manufacturer,  and  the  location  of  the 
factory. 

The  laws  which  tend  to  avoid  or  at  least  to  reduce  to  a  min- 
imum the  danger  of  explosion  during  transportation  of  explo- 
sives are  very  numerous.  Since  explosion  can  result  either  from 
fires  or  by  percussion,  the  laws  prescribe  rules  tending  to  avoid 
accidents  produced  by  these  causes.  To  avoid  fires  it  is  pre- 
scribed that  the  explosives  be  transported  in  separate  and  sealed 
cars,  in  which  no  more  than  a  prescribed  quantity  can  be  placed 
at  a  time.  In  cars  containing  explosives,  fires,  lights,  and  smok- 
ing are  absolutely  forbidden.  The  cars  must  neither  be  attached 
to  the  train  close  to  the  locomotive  nor  near  cars  containing 
inflammable  materials,  and  the  loading  and  unloading  of  these 
cars  must  be  made  in  the  daytime,  it  being  absolutely  prohibited 
at  night.  To  avoid  the  danger  of  explosion  by  percussion  it 
is  generally  prescribed  that  all  materials  must  be  so  well  packed 
as  to  entirely  fill  the  box  without  leaving  any  void;  that  the 
boxes,  barrels,  etc.,  containing  the  explosives  must  be  so  tightly 


74  EARTH  AND  ROCK  EXCAVATION. 

packed  into  the  cars  that  even  the  slightest  movement  is  impos- 
sible ;  that  boxes  shall  not  contain  nails  or  iron  bands,  and  finally 
the  use  of  hammers,  chisels,  and  other  iron  and  steel  tools  inside 
the  cars  is  forbidden.  The  boxes  containing  detonators  must 
be  stored  in  separate  cars  from  those  containing  explosives. 
The  regulations  for  the  transportation  of  the  explosives  upon 
ordinary  roads  go  into  even  more  detail,  so  as  to  describe  even 
the  form  of  the  brake  to  be  used  in  the  cars  in  going  down-grade, 
where  to  stop  at  night,  the  manner  of  making  short  stops  within 
the  city  limits,  how  to  cross  villages  and  towns,  the  streets  to  be 
avoided  and  those  through  which  it  is  allowable  to  pass,  and 
a  thousand  of  other  details.  When  the  transportation  of  the 
explosive  is  made  on  water  by  means  of  vessels  some  govern- 
ments compel  the  vessel  to  carry  a  special  flag  and  night  signal 
so  that  it  can  be  recognized  from  far  away. 

In  this  country  there  are  no  special  laws  for  the  transporta- 
tion of  explosives;  every  railroad  company,  however,  enacts 
special  rules  so  as  to  insure  itself  against  the  liability  of  paying 
great  damages  to  persons  or  properties  in  case  of  explosion. 
These  special  and  various  regulations  are  based  upon  the  same 
principle  as  the  European  laws,  the  only  difference  being  that 
they  are  inspired  by  the  desire  for  safety 'and  not  by  any  fear 
of  rebellion  or  conspiracy,  and  consequently  all  the  obstructive 
rules  regarding  this  point  are  here  happily  omitted. 

Storage  of  Explosives. — The  storage  of  explosives  is  regulated 
by  laws  which  are  too  strict  and  antiquated.  The  writer  has 
remarked  in  Engineering  that  in  the  city  of  New  York  the 
laws  allow  only  a  maximum  deposit  of  62J  Ibs.  of  dynamite, 
while  on  the  other  hand,  the  same  city  compelled  one  of  the 
sub-contractors  of  the  rapid-transit  railroad  to  use  not  less 
than  500  Ibs.  of  dynamite  per  day,  which  could  be  stored  at  only 
two  points.  This  means  that  even  in  the  city  of  New  York 
the  law  regarding  the  storage  of  the  explosives  is  antiquated 
and  entirely  insufficient  to  meet  the  requirements  of  works  of 
the  magnitude  undertaken  to-day. 

The  regulations  governing  the  storage  of   explosives  tend  to 


BLASTING — EXPLOSIVES.  75 

prevent  the  causes  of  explosion,  and  are  designed  so  that  in 
case  of  an  accident  the  explosjon  produces  the  smallest  damage 
possible  under  the  circumstances. 

Large  quantities  of  explosives  are  usually  stored  when  the  daily 
quantity  of  them  to  be  employed  in  the  work  is  great  and  the 
supply  cannot  be  obtained  every  day,  but  at  great  intervals  from 
one  consignment  to  another.  Such  a  large  deposit  of  explosives 
should  be  very  carefully  watched  to  avoid  the  causes  producing 
explosions,  which  are  spontaneous  decomposition  of  the  ingredients 
contained  in  the  explosives,  fire,  and  percussion.  To  prevent 
the  decomposition  of  the  substances  forming  the  explosives  it 
is  necessary  to  locate  the  store  in  a  very  dry  place,  and  the  tem- 
perature inside  the  room  should  neither  fall  below  8°  C.  nor  be 
higher  than  30°  C.  The  explosives  must  be  stored  in  their  original 
packages  as  they  came  from  the  factory,  with  the  difference  that 
the  cover  of  the  boxes  should  be  raised  so  as  to  expose  the  ex- 
plosive to  the  air  and  so  that  they  can  be  easily  watched  and 
any  alteration  detected.  The  decomposition  of  nitroglycerine 
products  is  generally  detected  by  a  kind  of  perspiration  which 
collects  on  the  outside  wrappers  of  the  explosive.  The  boxes 
containing  explosives  thus  affected  should  be  taken  out  of  the 
storage  immediately  and  opened.  These  boxes  should  then  be 
carried  to  a  distant  isolated  place  and  the  explosives,  liberated 
of  their  wrapping,  should  be  spread  on  the  ground,  forming  a 
very  thin  stratum,  and  burned.  Nearly  all  the  explosions 
of  stored  explosives  on  record  were  exclusively  due  to  the  decom- 
position of  the  ingredients  forming  the  blasting  substance.  The 
precautions  to  be  used  to  prevent  explosions  caused  by  fire  and 
percussions  are  the  same  that  are  taken  in  transportation  and 
already  discussed,  but  it  is  necessary  to  have  the  nitroglycerine 
products  and  the  detonators  stored  in  separate  rooms. 

In  order  to  have  the  smallest  possible  damage  in  case  of  an 
explosion,  it  is  necessary  to  locate  the  storehouse  for  explosives 
remote  from  any  dwelling  or  village;  to  build  it  of  light  scantlings 
instead  of  heavy  masonry,  so  as  to  oppose  the  least  resistance 
to  the  gases,  and  for  the  same  purpose  it  will  be  convenient 


76  EARTH  AND  ROCK  EXCAVATION. 

to  surround  and  even  cover  the  building  with  very  loose  earth 
or  sand.  According  to  the  indicated  principles,  the  engineer  hi 
charge  of  the  work  will  prescribe  special  rules  tending  to  insure 
the  safety  of  men  and  property,  and  see  that  they  are  strictly 
observed. 


CHAPTER  VII. 

ROCK  EXCAVATION  BY  BLASTING;  FUSES,  FIRING,  AND  BLASTING. 

Fuses.— When  gunpowder  is  used  as  the  explosive  for  ex- 
cavating rock  it  is  usually  ignited  by  the  Blickford  match.  This 
match,  or  fuse  as  it  is  more  commonly  called,  consists  of  a  small 
rope  of  yarn  or  cotton  having  as  a  core  a  small  continuous  thread 
of  fine  gunpowder.  To  protect  the  outside  of  the  fuse  from 
moisture  it  is  coated  with  tar  or  some  other  impervious  substance. 
These  fuses  are  so  well  made  that  they  burn  very  uniformly  at 
the  rate  of  about  1  ft.  in  20  seconds;  hence  the  moment  of  ex- 
plosion can  be  pretty  accurately  fixed  before- 
hand by  cutting  the  fuse  to  the  proper  length. 
Blickford  matches,  especially  when  coated  with 
tar,  have  the  defect  of  burning  with  a  bad  odor, 
and  this  is  very  objectionable  when  the  work  is 
being  done  in  closed  spaces,  as  in  a  tunnel. 
Other  fuses  have  been  invented  to  do  away 
with  this  trouble,  and  those  of  Rizha  and 
Franzl  are  the  best  known  of  these.  The 
former  has  many  advantages,  but  it  burns  too 
rapidly,  about  3  ft.  per  second,  and  is  expen-  FlG- 

sive;  the  latter  consists  of  a  small  hollow  rope  filled  with  dyna- 
mite and  is  dangerous. 

It  has  already  been  remarked  that  dynamite  does  not  explode 
by  ignition,  but  by  percussion;  consequently  the  Blickford  match 
alone  cannot  be  used  with  dynamite.  It  can,  however,  be  used 
to  ignite  and  explode  a  cartridge  which  will  in  turn  explode 
the  dynamite.  These  cartridges  consist  of  small  copper  cylinders 
containing  fulminate  of  mercury,  and  are  attached  to  the  end 

77 


78 


EARTH    AND    ROCK    EXCAVATION. 


of  the  fuse  which  is  inserted  in  the  dynamite.  The  firing  of 
explosives  by  means  of  the  Blickford  match  is  very  seldom  em- 
ployed at  present  in  the  excavation  of  rock  for  public  work.  Blasts 
are  usually  fired  by  electricity,  which  is  considered  preferable, 
because  several  blasts  can  be  fired  simultaneously,  and  because 


FIG.  31. 

the  current  is  turned  on  at  a  great  distance,  thus  affording  greater 
safety  to  the  workmen. 

The  method  of  electric  firing  generally  employed  in  America 
is  known  as  the  connecting-series  method  and  consists  in  firing 
•  several  holes  simultaneously.  The  arrange- 
ment and  connection  of  the  wires  are  shown 
by  the  diagram  Fig.  31.  Before  referring 
to  this  diagram,  however,  it  is  necessary  to 
state  that  each  hole  charged  with  dynamite 
is  provided  with  a  detonator.  This  consists 
of  a  capsule  containing  fulminate  of  mercury. 
Two  wires  enter  this  capsule  from  the  upper 
end  and  are  connected  at  their  bottoms  by  a 
very  fine  platinum  wire.  When  an  electric 
current  is  passed  through  the  two  wires,  the 
fine  wire  which  connects  them  offers  such 
resistance  to  the  current  that  it  becomes  red- 
hot  and  ignites  and  explodes  the  fulminate. 
Fig.  32  is  a  vertical  section  of  a  detonator 
of  the  character  described.  In  blasting  one 
of  these  detonators  is  placed  in  the  middle  stick  of  dynamite 
in  each  hole.  Referring  now  to  Fig.  31,  the  numerals  1,  2,  3,  and 
4  represent  as  many  detonators  in  separate  holes.  The  wires  of 
these  detonators  are  connected  as  indicated  by  splicing  to  them 


FIG.  32. 


BLASTING — FUSES    FIRING,  ETC.  79 

lengths  of  wire  reaching  from  hole  to  hole,  and  finally  the  first 
wire  of  hole  1  and  the  last  wire  of  hole  4  are  connected  to  the 
firing- wires  leading  to  tjie  blasfctoig- machine  A.  In  connecting 
the  various  wires  they  should  be  scraped  free  of  insulation 
and  twisted  together  in  close  contact,  and  then  the  burr-joint 
should  be  wound  with  tape  insulation.  Failure  to  wind  the 
joints  with  insulation  causes  trouble  very  often,  because  the  burr- 
wire  comes  in  contact  with  the  earth,  which  draws  the  current 
from  the  wires.  The  dimension  of  the  wires  connecting  the 
detonators  from  hole  to  hole  should  be  equal  to  that  of  the 
detonator  wires,  while  the  wires  leading  to  the  blasting-machine 
should  be  at  least  twice  the  diameter  of  the  detonator  wires. 

The  blasting-machine  illustrated  in  Fig.  30  consists  of  a  wooden 
box  enclosing  a  device  fitted  to  revolve  an  armature  wound  to  a 
very  high  resistance.  The  rapid  revolution  of  the  armature  by 
pulling  up  the  operating-bar  generates  an  electric  current  of  high 
electromotive  power,  which,  at  the  moment  of  its  maximum  inten- 
sity, is  sent  out  to  the  outside  circuit  in  which  are  the  detonators, 
the  explosion  of  which  is  instantly  accomplished.  These  machines 
are  operated  by  a  very  easy  and  simple  motion,  which  works 
smoothly  and  without  any  strain  upon  the  parts.  After  being 
pulled  up  to  fire,  the  operating-bar  will  fall  back  into  its  place  of 
its  own  weight  and  is  ready  to  be  used  again.  On  account  of  its 
special  construction,  in  which  the  power  is  obtained  by  pulling 
up  the  bar,  this  blasting-machine  is  commonly  called  the  pull-up 
machine.  It  is  built  in  different  sizes,  the  smaller  with  a  firing 
capacity  of  from  20  to  30  holes,  and  the  larger  with  a  firing  capac- 
ity of  from  75  to  100  holes.  The  operation  of  firing  is  as  follows: 
The  operator  turns  down  the  two-hinged  iron  plates  at  the  bottom 
of  the  box,  and  stands  with  his  feet  on  them  to  hold  the  machine 
down;  he  then  pulls  the  bar  up  with  both  hands  with  one 
continuous  rapid  stroke,  and  the  blast  is  fired.  The  quicker  the 
bar  is  pulled  up  the  more  current  the  machine  wih1  generate. 

Tamping. — After  a  blasting-charge  is  placed  in  the  hole  it  is 
covered  by  tamping,  which  is  a  material  placed  there  to  prevent 
the  gases  of  explosion  from  escaping  into  the  air.  Tamping  is 


80  EARTH  AND  ROCK  EXCAVATION. 

absolutely  necessary  with  gunpowder,  but  it  can  be  omitted  when 
the  explosive  substance  is  a  nitroglycerine  compound.  Gun- 
powder explodes  slowly,  and  if  the  gases  find  an  easy  exit  they 
escape  without  shattering  the  rock  much,  if  at  all;  hence  the 
necessity  of  closing  all  exit.  This  is  done  by  filling  the  hole  above 
the  charge  with  damp  clay  which  is  well  rammed  into  place 
by  means  of  a  wooden  tool  called  a  tamping-rod,  illustrated 
by  Fig.  33.  As  will  be  seen,  this  tool  consists  of  a  small  wooden 
cylinder  attached  to  a  handle  of  the  same  material, 
the  cylinder  being  provided  with  a  groove  in  one  side 
for  the  fuse-wires.  No  iron  tool  should  be  used  in 
tamping  because  of  the  danger  of  striking  a  spark 
from  the  rock  by  a  chance  blow  and  thus  prematurely 
exploding  the  blast.  To  protect  the  powder  from  being 
wetted  by  the  clay  a  layer  of  paper,  felt,  dry  cotton,  or 
other  substance  is  placed  over  the  charge  before  insert- 
ing the  clay.  With  dynamite  the  explosion  is  so  sudden 
that  the  gases  have  no  time  to  escape,  and  tamping  is 
consequently  not  required.  It  is,  however,  commonly 
used,  but  without  being  rammed  into  place. 

Firing. — The  operation  of  firing  the  blasts  should  be 
entrusted  only  to  the  foreman  of  blasters  or  to  some 
very  careful  workman.  The  following  is  the  mode  of 
procedure  usually  followed  in  firing:  After  all  the 
IG.  33.  holes  have  been  connected  with  the  leading  wires  of 
the  blasting-machine  a  danger-signal  is  given  by  blowing  a  whistle 
or  posting  men  with  red  flags  around  the  danger-zone.  Upon  this 
signal  all  men  leave  the  vicinity  of  the  blast,  and  outsiders  are 
prevented  from  approaching.  All  persons  being  out  of  danger, 
the  foreman  orders  the  blast  to  be  fired.  Upon  this  order,  and 
not  until  then,  the  leading  wires  are  attached  to  the  blasting- 
machine,  and  the  machine  is  operated  as  previously  described. 
As  soon  as  the  blast  is  fired  the  men  return  to  the  work,  and  traffic 
is  resumed  in  the  vicinity.  It  is  usually  found  convenient  to  fire 
the  blasts  at  12  o'clock  or  at  evening,  when  the  men  are  quitting 
work.  If  fired  at  other  times,  the  time  of  firing  is  so  much 


BLASTING — FUSES,  FIRING,  ETC.  81 

lost  from  the  men's  working  time,  and  the  greater  the  number  of 
men  the  greater  this  loss  is..  ^In  case  of  a  misfire  the  leading 
wires  are  detached  froth  the  blast  ing- machine  and  an  inspection 
is  made  to  locate  the  cause.  This  is  usually  found  to  be  the 
.grounding  of  the  current  because  of  defective  insulation;  this 
defect  being  repaired  by  insulating-tape,  the  wires  are  again  con- 
nected up  and  the  undischarged  hole  is  exploded.  Every  care 
should  be  taken  to  see  that  the  wires  are  in  proper  shape  before- 
hand, however,  as  it  is  a  trouble  and  waste  of  time  to  search  out 
defects  and  repair  them  afterwards,  especially  in  city  work,  where 
protecting  mattresses  and  timbers  have  to  be  removed  to  allow 
the  examination. 

Blasting. — The  cost  of  a  cubic  unit  of  rock  excavation  by 
blasting  depends  chiefly  upon  the  amount  of  work  and  the  quan- 
tity of  material  consumed.  The  work  consists  in  drilling  the 
holes,  and  the  material  is  the  quantity  of  explosive ;  both  of  these 
items,  viz.,  the  depth  and  frequency  of  the  holes  and  the  quantity 
of  explosive  employed,  should  be  fixed  by  the  engineer  after  a 
-careful  examination  and  series  of  experiments  on  the  rock  being 
worked.  The  writer  has  noticed  that  in  the  excavation  of  rock 
in  this  country  no  particular  attention  is  usually  given  to  these 
important  features  of  the  work.  In  every  excavation  it  should 
be  the  duty  of  the  engineer  to  fix  the  depth  of  the  holes,  their 
distance  apart,  and  the  amount  of  explosive  to  be  used;  and  in 
order  to  do  this  he  must  have  a  knowledge  of  the  phenomena  of 
explosion. 

When  explosives  are  ignited  a  sudden  development  of  gases 
results  which  produces  instantly  a  violent  increase  of  pressure, 
usually  accompanied  by  a  loud  report.  The  energy  of  the  explo- 
sion is  exerted  in  all  directions  in  the  form  of  a  sphere  having 
its  center  at  the  point  of  explosion,  and  the  waves  of  energy 
lose  their  force  as  the  distance  from  this  central  point  increases. 
The  energy  of  the  explosion  at  any  point  in  the  sphere  of  energy 
is,  therefore,  inversely  proportional  to  the  distance  of  this  point 
from  the  center  of  explosion.  Up  to  a  certain  distance  the 
energy  is  great  enough  to  shatter  the  rock  and  throw  it  violently 


82  EARTH  AND  ROCK  EXCAVATION. 

upward;  up  to  a  further  distance  the  energy  is  great  enough 
to  break  the  rock,  but  not  great  enough  to  throw  it  from  its  bed, 
and  from  this  last  point  to  the  limit  of  explosion  only  a  shock 
is  felt  which  decreases  in  severity  as  the  outer  limits  are 
approached.  There  are,  therefore,  three  concentric  spheres  of 
energy  or  force  within  the  blasting  sphere. 

When  the  surface  of  the  ground  intercepts  either  the  second  or 
the  third  sphere  the  gases  of  explosion  remain  in  the  ground,  but 
when  it  intercepts  the  first  sphere  the  explosion  detaches  a  cone- 
shaped  mass  of  materials  which  are  thrown  into  the  air.  This 
cone-shaped  pit  is  called  the  blasting-cone.  The  base  of  this 
cone  is  the  ground  -surf  ace,  and  its  apex  is  the  point  of  explosion; 
the  smallest  distance  between  the  apex  and  the  base  is  the  line 
of  least  resistance.  To  secure  the  most  effective  blast  the  ground- 
surface  should  be  tangent  to  the  first  sphere  of  energy,  as  then 
the  rock  will  be  thoroughly  shattered  but  not  thrown  upward. 
When  a  large  quantity  of  rock  is  thrown  high  into  the  air  it 
means  that  a  large  quantity  of  gas  has  been  wasted  which  should 
have  been  utilized  in  shattering  the  rock. 

In  blasting  the  quantity  of  the  mass  detached  from  the 
natural  bed  can  be  assumed  as  equal  to  the  volume  of  the  blasting- 
cone  and  is  consequently  given  by 

F  =  1.05/i3n2, 

in  which  n  is  the  inclination  of  the  generatrices  of  the  cone  in 
respect  to  the  axis,  and  h  is  the  smallest  distance  between  the 
point  of  explosion  or  apex  of  the  blasting-cone  and  the  ground- 
surface,  or  the  line  of  least  resistance.  When,  as  usual,  n  =  l 
the  volume  of  the  blasted  material  is  given  by 


and  consequently  the  volume  of  the  blasted  rock  is  proportional 
to  the  cube  of  the  line  of  least  resistance,  or,  what  is  the  same, 
to  the  cube  of  the  depth  of  the  holes. 

When  the  rock  to  be  blasted,  instead  of  having  only  one 
surface  to  which  the  hole  is  perpendicular,  has  two  surfaces  at 


BLASTING-r-FUSES,  FIRING,  ETC.  83 

right  angles  to  each  other,  wi£h*  the  hole  a  continuation  of  one  of 
the  surfaces,  the  volume  of  th&  blast  will  be  only  one-half  the 
blasting-cone  and  the  "detached  mass  will  be 


When  the  hole  is  drilled  at  the  intersection  of  these  surfaces 
only  one-fourth  the  volume  of  the  blasting-cone  will  be  detached 
and  the  mass  of  detached  rock  will  be 

F  =  0.26/i3. 

From  these  facts  and  from  the  experiments  made  on  a  cube 
and  reported  in  all  the  text-books  on  blasting  which  showed 
that  the  efficiency  of  blasting  increases  with  the  number  of  free 
surfaces  of  attack,  it  can  be  deduced  that  the  efficiency  of  blast- 
ing is  directly  proportional  to  the  free  surface  of  the  rock 
attacked. 

Knowing  the  quantity  of  rock  detached  at  each  blast,  which 
has  been  observed  to  be  proportional  to  the  depth  of  the  holes, 
the  distance  apart  of  the  holes  is  readily  determined  to  be  equal 
to  the  depth  of  the  holes.  From  the  experiments  of  Mr.  Hofer 
it  is,  however,  known  that  the  quantity  of  rock  detached  by 
mines  or  groups  of  holes  fired  simultaneously  is  double  that 
detached  by  the  same  number  of  holes  exploded  in  succession. 
This  is  a  fact  of  great  importance  to  engineers  and  constructors. 
While  the  distance  apart  of  the  holes  should  be  equal  to  the 
depth  of  the  holes  in  isolated  firing,  it  may  be  from  1J  to  2  times 
this  depth  for  simultaneous  firing.  The  most  expensive  item 
in  the  excavation  of  rock  is  the  drilling  of  the  holes  for  the  blasts. 
Since  the  cost  of  drilling  in  the  same  material  is  constant  per 
unit  of  length  of  hole,  while  the  quantity  of  rock  detached 
increases  with  the  cube  of  the  depth  of  the  holes,  if  the  greatest 
efficiency  of  blasting  is  to  be  had  it  is  necessary  to  have  deep 
holes.  The  deeper  the  holes  the  smaller  will  be  the  required 
number  of  feet  drilled  per  unit  of  volume  excavated.  The  most 
convenient  depth  of  hole  for  practical  work  is  from  8  to  12  ft., 


84  EARTH  AND  ROCK  EXCAVATION. 

and  usually  the  depth  of  hole  should  be  about  10  ft.  When, 
therefore,  the  depth  to  be  excavated  is  great  it  should  be  divided 
into  benches  10  or  12  ft.  deep.  Once  the  depth  of  the  holes 
is  determined  it  is  a  simple  matter  to  locate  their  distance  apart, 
since  this  should  be  equal  to  the  depth  of  hole  as  a  minimum, 
and  not,  as  many  contractors  assume  it,  from  2  to  3  ft.  apart. 

The  preceding  discussion  applies  to  homogeneous  rocks,  but 
these  are  seldom  met  with  in  excavation.  The  rock  is  usually 
stratified,  and  even  when  it  is  not  its  solidity  and  strength  are 
not  uniform.  As  a  rule,  any  rock  is  more  resistant  to  disruption 
in  a  direction  perpendicular  to  its  quarry-bed  than  in  a  direction 
parallel  to  it;  consequently  in  blasting  the  waves  of  energy  find 
greater  resistance  in  one  direction  than  in  the  other,  and  the  rock 
will  break  unsymmetrically  with  respect  to  the  axis.  Hence, 
instead  of  a  sphere  of  action  as  described  above,  we  have  an  ellip- 
soid with  the  greater  axis  parallel  to  the  direction  of  the  strata, 
or  the  quarry-bed  of  the  rock.  This  ellipsoid  is  seldom  of  regular 
form,  since  many  circumstances,  such  as  voids,  fissures,  veins  of 
other  materials,  tried  to  make  it  irregular.  That  the  waves  of 
force  spread  in  the  form  of  an  ellipsoid  may  also  be  deduced  from 
the  fact  that  the  center  of  explosion  is  a  line  and  not  a  point. 
If  there  were  no  other  controlling  considerations,  it  might  be 
assumed  as  a  practical  rule  to  follow  in  work  that  the  longer  the 
axis  of  the  charge  the  greater  would  be  the  ellipsoid  of  energy, 
but  other  considerations  make  it  necessary  to  fix  the  charge 
according  to  more  scientific  principles. 

In  speaking  of  explosives  it  was  remarked  that  the  force  of 
the  gases  of  explosion  varies  in  the  same  ratio  as  the  weight  of 
the  explosive.  From  the  above  discussion  it  has  been  deduced 
that  in  blasting,  other  conditions  being  equal,  the  volume  of 
detached  rock  is  proportional  to  the  line  of  least  resistance,  or  to 
the  cube  of  the  depth  of  the  hole.  Therefore  to  produce  the 
greatest  effect  the  charge  should  increase  with  the  cube  of  the 
depth  of  the  hole.  In  practical  work,  however,  this  quantity 
should  be  multiplied  by  a  certain  coefficient,  depending  upon  the 
force  of  the  gases  of  explosion  and  the  nature  of  the  rock  blasted. 


BLASTING  —  FUSES,  FIRING,  ETC.  85 

According  to  G.  G.  Andre,  the  quantity  Q  of  the  explosive  can 
be  represented  by  the  formula 


in  which  c  is  the  coefficient  and  v  is  the  length  of  the  line  of  least 
resistance.  The  quantity  Q  is  expressed  in  pounds,  and  the  dis- 
tance v  in  feet.  The  coefficient  c  is  fixed  according  to  experiment, 
and  generally  varies  between  0.3  and  0.45  for  gunpowder,  and 
between  0.06  and  0.09  for  dynamite  and  other  nitroglycerine 
compounds.  The  engineer  should  not  only  fix  the  coefficient  c 
after  a  series  of  experiments  upon  the  rock  being  blasted,  but  he 
should  instruct  the  blasters  as  to  the  different  charges  to  be  used 
under  the  various  conditions  of  work.  Thus,  for  instance,  the 
same  rock  may  be  attacked  in  a  direction  perpendicular,  parallel, 
or  inclined  to  the  strata,  and  in  each  of  these  cases  a  different 
charge  should  be  used.  The  charge  should  also  vary  with  the 
free  surface  of  the  blast.  In  blasting  the  first  holes  in  driving 
the  heading  of  a  tunnel  or  the  bottom  of  a  shaft,  they  should  be 
charged  with  more  explosive  than  is  used  in  any  of  the  succeed- 
ing rounds  of  holes,  since  they  have  to  detach  a  mass  of  rock  bound 
in  on  all  sides  but  one,  while  for  the  other  rounds  the  hole  already 
blasted  forms  free  surfaces  for  the  action  of  the  blast.  For  the 
same  reason  it  is  usual  to  employ  a  more  powerful  explosive  for 
these  first  holes. 

It  is  often  observed  in  excavating  rock  by  blasting  that,  with 
holes  of  the  same  depth  containing  the  same  amount  of  explosive 
in  the  same  rock,  the  effect  will  be  very  small  in  one  case  and 
much  greater  in  another  case.  Owing  to  this  fact,  accidents  often 
happen  for  which  the  blaster  is  innocent,  but  for  which  he  is  never- 
theless frequently  blamed  and  punished  by  law.  Experiments 
made  recently  by  Messrs.  Roux  and  Sarrau  give  a  scientific  expla- 
nation of  this  phenomenon.  These  gentlemen  claim  that  all  explo- 
sive substances  can  explode  hi  two  ways:  the  one  by  means  of 
heat  they  call  explosion;  the  other  by  means  of  heat  under  great 
pressure  they  term  detonation.  In  explosion  the  development  of 


86  EARTH  AND  ROCK  EXCAVATION. 

the  gases  produced  by  the  heat  of  combustion  is  relatively  slow, 
it  taking  some  time  for  the  process  to  reach  all  portions  of  the 
charge.  This  time  is  infinitesimally  small,  of  course,  but  it  is 
appreciable.  In  detonation  the  explosion  of  every  part  of  the 
charge  is  simultaneous  and  instantaneous.  The  effects  produced 
by  explosion  and  by  detonation  differ;  in  explosion  the  effect  is 
to  raise  up  and  force  down  the  surrounding  material,  and  in  deto- 
nation the  effect  is  to  crush  this  material.  According  to  Messrs. 
Roux  and  Sarrau,  gunpowder,  which  usually  explodes,  will  also 
detonate  when  ignited  by  means  of  nitroglycerine  or  fulminate 
of  mercury,  and  then  the  energy  of  the  blast  is  much  greater 
than  the  sum  of  the  energy  of  the  two  materials  explode'd  sepa- 
rately. The  detonation  of  dynamite  is  obtained  by  means  of 
capsules  of  fulminate  of  mercury  tightly  pressed  into  the  dyna- 
mite. If  the  capsules  are  not  strongly  pressed  into  the  dynamite, 
only  a  portion  of  it  will  detonate,  while  the  other  portion  explodes. 
Messrs.  Roux  and  Sarrau  experimented  on  bombs  of  equal  dimen- 
sions, and  they  found  that  it  required  only  4  grams  of  dynamite 
to  break  them  when  detonated,  while  it  required  16  grams  to 
break  them  when  exploded. 

A  comparison  of  the  relative  energy  of  explosion  and  detona- 
tion of  different  substances  is  given  in  the  following  table,  in 
which  the  energy  of  gunpowder  is  taken  as  unity: 

Explosive.  Explosion.  Detonation. 

Fulminate  of  mercury 9 . 28 

Gunpowder 1  4 . 34 

Nitroglycerine 4.8  10. 13 

Guncotton 3  6.4 

The  great  advantage  to  be  secured  by  obtaining  full  detona- 
tion of  dynamite  instead  of  part  detonation  and  part  explosion 
can  readily  be  seen  from  this  table.  If  all  the  dynamite  could 
in  blasting  be  detonated,  only  half  the  quantity  now  employed 
would  be  required.  This  would  be  a  great  advantage  not  only 
by  reducing  the  cost  of  explosives,  but  by  cutting  in  half  the 


BLASTING — FUSES,  FIRING,  ETC.  87 

amounts  handled  and  thus  reducing  the  chance  of  accidental 
explosion. 

In  conducting  blasting  operations  in  city  streets  or  in  thickly 
settled  districts  it  is  the  usual  practice  to  cover  the  holes  with 
a  protecting  mattress  before  firing  them.  Such  mattresses  are 
usually  made  of  logs  about  1  ft.  in  diameter  loosely  chained  to- 
gether into  a  mattress-like  bunch.  In  New  York  City  each 
mattress  usually  consists  of  ten  logs,  and  enough  mattresses  are 
used  to  cover  the  full  area  of  the  blast  ing-cone.  Over  these  logs 
is  placed  a  heavy  netting  made  of  1J-  to  IJ-in.  manila  rope,  or 
else  a  sheet  of  tin,  usually  a  section  of  discarded  tin  roofing.  Logs 
and  rope  nets  are  preferable  to  logs  and  tin  sheets.  The  logs 
should  be  loosely  tied  together  so  that  they  give  an  elastic  mat- 
tress to  absorb  the  force  of  the  explosion;  if  fastened  rigidly 
together  they  will  break  and  splinter.  The  operation  of  these 
mattresses  is  as  follows:  They  rise  into  the  air  from  the  force 
of  the  blast,  but  confine  the  flying  stones  underneath  and  imme- 
diately drop  back  to  near  their  original  position  because  of  their 
great  weight. 


CHAPTER  VIII. 

EARTH  EXCAVATION:    HAND-TOOLS;  MACHINE  EXCAVATION. 

HAND-TOOLS. 

Shovels. — The  simplest  and  perhaps  the  oldest  tool  employed 
in  the  excavation  of  earth  is  the  shovel.  This  tool  as  shown  in 
Fig.  34  consists  of  a  wooden  handle  with  a  flattened  iron  or  steel 
scoop  or  blade  at  one  end.  Shovels  are  made  of  different  shapes 
for  different  materials,  and  they  also  vary  in 
form  with  the  usage  of  different  countries.  For 
excavating  loose  earths  like  quicksand  and 
mud  a  blunt-pointed  shovel  is  employed, 
while  for  excavating  harder  soils  a  sharp- 
pointed  shovel  is  employed.  Another  differ- 
ence is  the  length  of  the  handle,  which  is  some- 
times long  and  sometimes  short.  In  Conti- 
nental Europe  the  long-handled  shovel  is 
generally  employed,  while  in  America  it  is 
more  customary  to  use  shovels  with  short 
handles.  The  writer  thinks  that  this  American 
practice  has  little  more  than  prejudice  to 
recommend  it.  The  shovel  is  a  lever  whose 
fulcrum  is  where  the  workman  grasps  the 
handle  with  his  left  hand  and  to  which  the 
power  is  applied  at  the  upper  extremity  of  the 
handle.  With  a  long-handled  shovel,  there- 
FIG.  34.  fo^  the  lever-arm  is  longer  and  the  power 

employed  smaller,  and  consequently  the  amount  of  work 
performed  by  the  laborer  is  greater  than  if  he  use  a  shovel  with 
a  short  handle.  Another  advantage  of  the  long-handled  shovel 

88 


EARTH  EXCAVATION:  HAND-TOOLS. 


is  that  the  laborer  works  in  an  upright  position,  and  his  endurance 
will  be  greater  than  if  compelled  to  work  bent  over  with  a  short- 
handled  shovel.  It  is  this  line  of  reasoning  that  has  led  European 
engineers  and  contractors  to  favor  the  long-handled  shovel.  The 
author  endeavored  to  investigate  the  reasons  for  the  preference 
of  American  engineers  and  contractors  for  the  short-handled 
shovel,  but,  with  the  exception  that  it  was  more  handy  and  easy 
to  transport,  no  plausible  reason  could  be  discovered.  A  member 
of  one  of  the  largest  firms  selling  contractor's  tools  in  America, 
in  evident  surprise  that  such  a  question  should  be  asked,  said, 
"Write  on  my  authority  that  the  long-handled  shovel  is  the  lazy 
man's  tool/'  but  he  gives  no  reasons  beyond  this  bold  statement. 
Now  since  the  laborer  is  to  the  contractor  and  engineer  simply 
a  working  machine,  utilized  just  for  the  amount  of  work  it  will 
perform  in  a  day,  it  is  necessary  to  obtain  from  this 
human  machine  the  greatest  possible  amount  of 
work,  and  this  is  accomplished  only  wThen  it  is 
allowed  to  work  under  the  most  favorable  condi- 
tions. For  this  reason  it  would  seem  that  the 
long-handled  shovel  should  be  preferred  to  the 
short-handled  one.  In  fact,  while  in  this  country 
contractors  consider  it  a  fair  day's  work  for  a  man 
to  load  from  7  to  8  cu.  yds.  into  a  cart,  European 
engineers  calculate  15  cu.  m.  as  the  average  day's 
work  of  a  man  using  the  long-handled  shovel.  This 
difference  of  work  obtained  by  the  two  different  tools 
is  so  great  as  to  command  the  greatest  consideration. 
Spade. — When  the  soil  although  loose  yet  offers 
some  resistance  to  being  removed  from  its  natural 
bed  a  stronger  tool  than  a  shovel  is  employed.  This 
is  the  spade,  the  construction  of  which  is  shown 
by  Fig.  35.  The  blade  is  nearly  flat  and  is  made 
of  heavy  steel  plate  reinforced  at  the  top  edge.  The 
handle  is  of  wood  with  a  cross-grip  at  the  top.  In 
operation  the  spade  is  pressed  into  the  ground  with  the  foot  by 
thrusting  against  the  reinforced  edge.  In  this  country  the  spade 


90  EARTH  AND  ROCK  EXCAVATION. 

is  seldom  used  for  general  excavation,  preference  being  given  to 
a  strong  shovel  with  a  sharp  point  and  a  reinforced  top  edge.  The 
use  of  this  shovel  makes  it  unnecessary  for  the  laborer  to  change 
from  spade  to  shovel,  thus  losing  time,  or  to  handle  soft  ma- 
terial with  a  narrow-bladed  spade.  The  efficiency  of  work  with 
the  spade  varies  with  the  character  of  the  material,  but  with 
average  material  from  14  to  18  cu.  yds.  per  day  can  be  handled. 
At  wages  of  $1.00  per  day  this  makes  the  cost  of  simply  removing 
1  cu.  yd.  from  its  natural  bed  from  5J  to  7  cents. 

Pick. — In  soils  which  require  a  stronger  tool  than  a  spade  a 
pick  is  employed.  This  tool  with  its  wooden  handle  and  long 
double-pointed  head  is  familiar  to  every  one  and  needs  no  descrip- 
tion. In  some  cases  both  points  are  sharpened  with  a  square 
taper,  but  often  one  point  is  chisel-edged  either  parallel  to  or 
perpendicular  to  the  axis  of  the  handle.  In  operation  the  sharp 
point  of  the  tool  is  struck  into  the  ground,  and  the  handle  is  used 
as  a  lever  to  pry  out  a  piece  of  earth.  The  chisel  edge  according 
to  its  direction  is  used  like  an  axe  or  like  a  mattock  or  hoe.  The 
efficiency  of  the  work  done  with  a  pick  varies  with  the  character 
and  conditions  of  the  soil.  It  is  generally  deemed 
to  be  from  twice  to  three  times  that  of  the  shovel, 
and  consequently  the  cost  of  removing  a  cubic  yard 
of  earth  by  means  of  the  pick  varies  from  3  to  6 
cents  per  cubic  yard. 

Sledge-hammer  and  Wedges. — Other  tools  which 
are  sometimes  used  for  excavating  earth  are  sledge- 
hammers and  wedges  The  sledge-hammers  employed 
for  this  purpose  may  be  of  the  same  shape,  weight, 
and  dimensions  as  those  used  in  the  excavation  of 
rock,  but  as  in  loose  soils  wooden  wedges  are  used, 
the  sledge  can  be  made  of  a  piece  of  heavy  wood, 
usually  cylindrical  in  form,  which  is  bound  with 
bands  or  hoops  of  iron  and  provided  with  a  long 
handle,  as  shown  by  Fig.  36.  The  wedges  are  made 
of  wood  and  are  much  larger  than  those  used  in  the  excavation  of 
rock;  they  are  from  18  ins.  to  2  ft.  long  and  from  8  to  12  ins. 


EARTH  EXCAVATION:  MACHINE  EXCAVATION.  91 

thick  on  top.  The  sledge  and  wedges  are  particularly  suitable 
for  breaking  down  steep  banks"  or  faces  of  earth.  The  mode  of 
procedure  is  to  drive  the  wedgefe  in  a  row  parallel  to  the  edge  of 
the  bank  and  a  little  back  from  it,  and  drive  them  until  a  seam  is 
opened  and  a  slice  of  the  bank  face  breaks  off.  The  higher  the 
bank  the  greater  is  the  efficiency  of  the  method.  Another  method 
of  removing  banks  by  wedges  is  first  to  cut  vertical  channels  or 
grooves  at  intervals  in  the  face  so  as  to  leave  buttresses  of  earth 
between  them.  The  grooves  are  made  about  1  ft.  wide,  and  the 
buttresses  left  are  4  or  5  ft.  wide  and  the  same  depth  as  the  chan- 
nels, or  about  3  ft.  When  the  whole  face  of  the  bank  has  been 
slotted  in  the  manner  described  the  buttresses  are  undermined 
by  cutting  a  horizontal  slot  through  them  close  to  the  floor  of 
the  excavation.  This  leaves  the  buttresses  suspended  and 
attached  to  the  bank  on  only  one  side.  They  are  then  detached 
by  means  of  wedges  in  a  manner  similar  to  that  already  described. 

Blasting. — In  open  country  away  from  habitations  it  is  often 
convenient  to  use  blasts  for  such  work  as  breaking  down  a  knoll 
of  earth.  A  charge  of  several  pounds  of  dynamite  of  about  30  per 
cent  nitroglycerine  is  inserted  in  the  ground  and  fired.  The 
explosion  loosens  and  breaks  up  the  earth,  so  that  it  can  be 
handled  by  shovels. 

Hydraulic  Excavation. — A  method  of  excavation  which  is 
very  cheap  and  which  can  be  employed  in  some  cases  where 
water  under  pressure  is  available  is  to  break  down  the  soil  by  a 
powerful  hose-stream  and  wash  it  away  through  wooden  flumes 
discharging  at  some  suitable  point.  This  method  of  excavation 
has  been  much  used  on  the  Pacific  coast  in  mining  and  for  filling 
in  railway  trestles. 

MACHINE     EXCAVATION. 

The  magnitude  of  modern  engineering  works  and  the  rapidity 
with  which  they  are  prosecuted  make  the  pick  and  shovel  too 
slow  a  tool  for  earth  excavation,  and  they  have  been  replaced 
by  excavating-machines  of  various  sorts  which  are  capable  of 
multiplying  many  fold  the  work  done  in  a  given  time  and  at  a 


92 


EARTH   AND    ROCK    EXCAVATION. 


given  cost.  Earth  excavation  consists  of  two  processes;  the  first 
is  the  displacement  of  the  soil  from  its  natural  bed,  and  the 
second  is  the  transferring  of  the  displaced  soil  to  vehicles  for  its 
removal.  Excavat ing-machines  must  perform  both  these  duties. 
Two  general  modes  of  procedure  are  followed  in  excavating 
earth;  one  is  to  remove  the  surface  by  scraping  off  thin  layers, 
and  the  other  is  to  remove  a  deep  cut  by  taking  successive  layers 
from  the  face  of  a  vertical  bank.  By  the  first  method  the 
excavating- machine  used  is  in  constant ,  motion,  and  by  the 
second  method  the  machine  does  very  little  traveling.  To  the 
first  class  of  machines  belong  the  plow,  the  scraper,  and  the 
New  Era  grader,  and  to  the  second  belong  various  forms  of 
digging-machines.  The  first  class  of  machines  is  operated  by 
horse-power,  and  the  second  class  by  steam-power.  For  sake  of 
convenience  the  various  forms  of  excavating-machines  on  the 
market  are  classified  according  to  their  manner  of  working  in  the 
following  table: 


Attacking  the  earth  all  along  the  surface. 


Plow. 

New  Era  grader. 


g                                                                       [  Machine  stands  on 
g                                                                            the  bank  to  be 
be  \                                   Machines  work-  1       excavated. 

i   Down-  digging; 
land-dredge. 

q 
•3 

ing     continu-  \ 

3 

1 
j3       Attacking      the 

ously. 

Machine  stands  on 
the  plane  of  the 
excavation. 

1  Up-digging  land- 
dredge. 

earth  in  banks. 

Standing    on    the 

! 

plane  of  the  ex- 

- Steam-shovel. 

Machines  work- 

cavation. 

i 

ing    intermit-  - 

tently. 

Standing  on  top  of  " 
the  bank  to  be 

Grabbing-buck- 

excavated. 

ets. 

Plow. — The  simplest  machine  for  breaking  the  ground  to 
destroy  the  cohesion  of  the  soil  is  the  ordinary  plow  employed 
for  agricultural  purposes.  The  essential  parts  of  this  implement 
are:  a  triangular-pointed  iron  or  steel  share  for  slicing  the  earth 
at  the  bottom  of  the  furrow;  a  mold-board  attached  to  the 
right  side  of  the  share  and  having  a  helicoidal  surface  to  turn 


EARTH  EXCAVATION:  MACHINE  EXCAVATION. 


93 


over  the  earth  cut  from  the  furrow;  a  standard  connecting  the 
mold-board  and  share  to  the  'beam,  and  a  beam  provided  with 
a  clevis  at  the  forward  end  ana  with  handles  at  the  rear  end. 
Sometimes  a  cutter  projecting  downward  from  the  beam  forward 
of  the  share  is  employed  for  compact  and  tough  soils.  Plows  of 


FIG.  37. 


various  forms  and  dimensions  are  found  on  the  market,  and  nearly 
every  manufacturer  lays  claim  to  superiority  because  of  some 
patented  attachment  or  improvement.  In  size  plows  vary  from 
those  which  can  be  hauled  by  two  and  four  horses  to  those  which 


FIG.  38. 

require  from  ten  to  twelve  horses  to  pull  them.  In  some  forms  of 
plows  the  beam  and  handles  are  of  wood,  as  shown  by  Fig.  37,  and 
in  others,  as  shown  by  Figs.  38  and  39,  the  beams  are  of  iron  and 
the  handles  wholly  or  partly  of  iron.  When  iron  beams  are 
used  they  are  generally  curved  so  that  the  share  and  mold-board 
are  connected  directly  without  the  necessity  of  a  standard.  Plows 
with  metal  beams  are  always  preferable,  as  they  are  stronger 
and  more  durable,  there  being  no  wood  to  decay. 

Plows  are  usually  employed  for  breaking  up  the  earth  so  that 
it  can  be  removed  by  drag  or  wheeled  scrapers,  and  when  used  in 


94 


EARTH    AND    ROCK    EXCAVATION. 


this  way  they  are  very  efficient  tools  for  cutting  down  a  large  area 
in  thin  layers.  The  depth  of  furrow  removed  varies  from  4  to  12 
ins.,  and  its  width  rs  about  1  ft.  According  to  Trau twine  a  plow 
drawn  by  two  horses  and  operated  by  two  men  will  break  up 
from  200  to  300  cu.  yds.  of  strong  heavy  soil  and  from  400  to  600 
cu.  yds.  of  ordinary  loam  per  day  of  ten  hours.  The  daily  running 
expenses  are  the  wages  of  the  men  and  the  keep  of  the  horses, 
and  they  may  be  estimated  at  SI. 50  and  75  cts.  each,  respectively 
which  gives  a  cost  of  1  to  1J  cents  per  cubic  yard  for  heavy  soil 
and  of  .5  to  .7  cent  per  cubic  yard  for  loam. 

The  form  of  plow  shown  by  Fig.  39  is  designed  especially 
for  breaking  up  turnpikes,  macadam  roads,  and  cemented  walks. 


FIG.  39. 

It  has  a  heavy  iron  beam,  to  which  the  point  is  secured  by  two 
strong  steel  plates.  The  point  is  made  of  tool-steel,  and  is  re- 
movable for  sharpening  or  renewal.  There  is  no  mold-board 
or  cutter.  The  handles  and  clevis  are  similar  to  those  of  ordinary 
plows.  These  plows  may  be  drawn  by  horses,  but  it  is  more 
common  to  operate  them  by  cables  from  stationary  engines,  par- 
ticularly where  the  work  is  breaking  up  macadam  road  or 
cemented  gravel. 

New  Era  Grader. — If  we  define  an  excavating-machine  as 
one  which  both  breaks  up  and  loads  the  earth,  then  the  plow 
does  not  belong  among  excavating-machines  The  only  reason 
for  not  including  it  among  hand-tools  is  that  it  is  operated  by 
horse-power.  The  New  Era  grader  is  a  true  excavating-machine, 


EARTH  EXCAVATION:  MACHINE  EXCAVATION.  95 

however,  as  it  both  breaks  up  the  'soil  and  loads  it  into  carts  for 
transport.  One  of  these  machines  is  shown  by  Figs.  40  and  41. 
Fig.  40  shows  the  excavating  mechanism  and  Fig.  41  shows  the 
loading  mechanism.  The  machine  is  made  entirely  of  steel. 
The  main  frame  is  arched  and  trussed  so  as  to  give  lightness 
combined  with  the  greatest  possible  strength  and  the  necessary 
flexibility  to  allow  the  machine  to  conform  to  the  uneven  surface 
of  the  ground  without  the  frame  straining,  twisting,  or  springing 
out  of  shape.  This  main  frame  is  mounted  on  a  truck  with  two 
driving-wheels  and  two  hind  wheels.  On  the  truck  there  is  a 
platform  where  the  operator  stands,  having  in  front  the  sprocket- 
wheels  for  regulating  the  carrier  or  elevator.  On  the  left  side 
of  the  main  frame  is  attached  the  plow-beam,  made  of  a  steel  I  beam. 
Perpendicular  to  the  plow-beam  there  is  a  standard  to  which  are 
bolted  the  plowshare  and  mold-board,  so  that,  properly  speaking, 
this  machine  can  be  considered  as  a  very  powerful  steel  plow  with 
the  cutter  partially  bolted  to  the  plowshare  and  the  whole  plow 
perfectly  fixed  to  the  frame.  In  order  to  give  stability  to  the 
machine  and  counteract  the  great  weight  of  the  carrier,  this 
powerful  plow  is  placed  at  the  outermost  point  of  the  main  frame 
of  the  truck.  As  in  any  other  plow,  there  is  the  mold-board 
which  turns  the  furrow  removed  from  the  soil  by  the  share; 
with  the  difference  that  the  furrow,  instead  of  falling  back 
on  the  ground  after  it  has  been  revolved,  falls  on  the  lower  end 
of  the  carrier  and  travels  along  it.  The  carrier  is  really  an  in- 
clined belt  conveyor  in  which  an  endless  belt  is  stretched  between 
two  revolving  drums  placed  at  the  extremes  of  a  frame  and  running 
on  rollers  placed  on  the  upper  side  of  the  frame.  When  one  of 
the  extreme  revolving  drums  is  moved  by  any  motive  power 
the  belt  is  compelled  to  turn,  and  consequently  in  traveling  along 
the  frame  it  will  carry  with  itself  any  material  which  has  been 
deposited  upon  it.  The  drum  at  the  upper  end  of  the  ladder  is 
usually  moved  by  a  suitable  arrangement  in  connection  with  the 
hind  axle  of  the  truck. 

When  the  machine  is  in  movement  the  plow  excavates  the 
earth,  which  is  deposited  on  the  lower  end  of  the  belt,  and  traveling 


98  EARTH  AND  ROCK  EXCAVATION. 

along  it  reaches  the  highest  point  and  falls  off.  If  now  a  wagon 
is  traveling  alongside  of  the  machine,  it  will  receive  the  discharged 
material  and  will,  thus  be  automatically  loaded.  Having  enough 
wagons  at  hand  so  that  as  soon  as  one  is  loaded  an  empty  one 
will  ;takes  it  place,  the  result  will  be  that  the  machine  will  not 
only  .  excavate  the.  ground,  but  also  automatically  load  the  ex- 
cavated material. 

The  carrier  is  from  15  to  22  ft.  long,  and  can  be  inclined  at 
any  angle  by  means  of  chains  passing  over  sheaves  supported  by 
a  steel  frame  attached  to  the  main  frame  of  the  machine  and 
wound  around  sprocket-wheels,  which  are  regulated  .by  the  oper- 
ator standing  on  the  platform  of  the  truck.  The  frame  of  the 
carrier  is  made  of  steel,  thus  giving  lightness  and  strength  at  the 
same  time.  On  each  side  of  the  upper  part  of  the  frame  of  the 
carrier  there  are  two  small  boards  which  keep  the  excavated 
materials  on  the  belt  and  prevent  their  falling  sideways.  The 
space  between  the  mold-board  of  the  plow  and  the  lower  end 
of  the  carrier  is  provided  with  a  simple  sand-lifting  attachment, 
making  it  possible  to  load  on  to  the  carrier  even  sandy  or  light, 
dry  soils. 

The  New  Era  grader  is  drawn  by  eight  horses  in  front  and 
four  behind,  hitched  to  a  push-cart.  It  had  been  observed  that 
when  the  motive  power  was  applied  only  in  front  of  the  machine 
this  was  liable  to  easily  stagger  either  on  account  of  the  inclination 
of  the  ground  or  of  the  small  resistance  met  in  the  work.  To  avoid 
this  and  in  order  to  have  the  machine  always  under  control,  it 
was  found  necessary  to  apply  the  motive  power  both  in  front 
and  at  the  back  of  the  machine.  The  four  horses  on  the  back 
are  hitched  abreast  and  driven  by  a  man  sitting  on  a  push-cart, 
which  is  a  simple  two-wheel  truck  with  a  small  seat.  The  shaft 
of  the  cart  is  very  long,  and  by  means  of  chains  is  strongly  con- 
nected to  the  main  frame  of  the  machine.  Fig.  42  illustrates  the 
push-cart  built  by  the  Western  Wheeled  Scraper  Company. 

The  New  Era  grader  will  work  in  any  soil  where  an  ordinary 
plow  can  be  used,  and  over  which  teams  and  the  machine  can  be 
driven.  The  plow  on  the  machine  will  handle  as  much  earth 


EARTH  EXCAVATION:  MACHINE  EXCAVATION.  99 

as  any  four  horses  plow.  Assuming  that  the  teams,  including 
the  stopping,  will  travel  at  the  rate  of  one  and  a  half  miles  per 
hour,  in  ten  hours  a  furrow  ISmiles  long,  1  ft.  wide,  and  6  ins. 
deep  will  be  placed  on  the  carrier,  which  is  equivalent  to  1460 
cu.  yds.  of  earth,  and  this  is  the  theoretical  efficiency  of  the 
machine.  Such  a  quantity  is  not  very  far  from  what  has  been 
really  obtained  in  practical  work.  As  a  rule  it  can  be  assumed 
that  it  is  capable  of  placing  in  grade  or  embankment  1000  cu.  yds. 
of  earth,  or  loading  from  500  to  600  wagons  of  1J  cu.  yds.  capacity 
each  in  a  ten-hour  day,  using  but  six  teams  and  three  men.  The 


FIG.  42. 

efficiency  of  the  New  Era  grader,  however,  depends  chiefly  upon 
the  soil  to  be  excavated;  in  light  and  sandy  soils  the  work  is  very 
close  to  its  theoretical  capacity,  while  it  can  be  assumed  at  only 
one-half  of  this  tnrough  clay  and  one- third  in  hard-pan  or  gravel. 
To  load  1000  cu.  yds.  in  ten  hours  a  wagon  must  be  at  the 
side  of  the  machine  every  thirty  or  fifty  seconds.  The  length  of 
the  haul  will  govern  the  number  of  teams  and  wagons  required. 
A  team  with  a  dumping-wagon  by  automatically  opening  the 
bottom  will  haul  90  ft.,  dump,  and  return  for  reloading  in  one 
minute.  When  the  haul  is  not  over  50  ft.  four  wagons  will  attend 


100  EARTH    AND    ROCK    EXCAVATION. 

the   machine.      For   each   additional   90   ft.  one  team  must  be 
added. 

The  cost  of  the  daily  work  of  the  New  Era  grader  is  given  by 
the  wages  of  the  men  and  the  hiring  of  the  horses,  which  is  assumed 
to  be  $18;  dividing  this  by  the  total  amount  of  the  work,  the 
cost  per  unit  of  volume  of  the  theoretical  efficiency  of  the  machine 

1  R 
will  be  ^777=  0.0128.     But  in  light  and  sandy  soils,  the  actual 

work  being  1000  cu.  yds.  per  day,  the  cost  per  unit  of  volume  will 

18 
be  JQQQ  =  0.018,*   and  in  hard  soils,  like  those  encountered  in  the 

excavation  of  the  Chicago  Drainage  Canal,  in  which  the  efficiency 
of  the  machine  was  508  cu.  yds.,  the  cost  per  unit  of  volume  is 

18 

=0.035. 


New  Era  graders  are  extensively  used  in  the  excavation  of 
canals,  and  are  very  valuable  in  constructing  irrigation-ditches. 
They  are  also  used  with  advantage  in  loading  earth  into  wagons 
when  the  haul  is  from  600  to  3000  ft.,  and  as  a  rule  they  give  best 
results  in  the  excavation  of  large  quantities  of  earth  extended 
over  a  large  area,  and  when  the  depth  of  the  excavation  is  not 
more  than  10  ft. 

The  New  Era  grader  just  described  and  illustrated  in  Figs. 
40  and  41  is  built  by  the  F.  C.  Austin  Mfg.  Co.  of  Harvey, 
111.,  while  the  cut  of  the  push-cart  has  been  taken  from  the  Cata- 
logue of  the  Western  Wheeled  Scraper  Company  of  Aurora,  111. 
This  latter  firm  is  building  another  similar  machine  built  on  the 
same  principles  as  those  of  the  New  Era  grader,  but  varying  in  the 
details,  called  the  elevating  grader,  wagon-loader,  and  ditcher. 
These  are  the  only  two  forms,  to  the  knowledge  of  the  writer, 
that  are  engaged  in  the  manufacture  of  this  kind  of  machines. 

Automobile  Steam  Grader  and  Ditcher.  —  Lately  a  new  machine 
has  been  introduced  on  the  market  by  the  Bunnell  Machinery  Com- 
pany of  Chicago,  111.,  and  is  illustrated  in  Fig.  43.  In  order  to 
lessen  the  operating  expenses  of  the  New  Era  grader,  thus  reduc- 
ing the  unit  of  cost  of  its  work,  made  up,  as  has  been  seen,  from 


OF  TH€ 

UNIVERSITY 

OF 


EARTH  EXCAVATION:  MACHINE  EXCAVATION. 


101 


the  large  number  of  horses  used  as  motive  power,  and  from  the 
employment  of  three  men,  two  as  drivers  and  one  as  operator, 
Mr.  M.  G.  Bunnell  undertook  $  substitute  steam  for  the  animal 
power,  and  the  result  was  the  automobile  steam  grader  and 
ditcher.  This  consists  of  a  fixed  plow  and  a  belt  conveyor,  like 
the  New  Era  grader  just  described,  with  the  exception  that, 
Instead  of  being  mounted  on  an  iron  frame,  they  are  supported 
by  a  tubular  boiler,  of  the  locomotive  type,  mounted  on  four 


FIG.  43. 

wheels.  The  two  front  wheels  turn  on  an  axle,  which  supports 
the  boiler  by  means  of  a  heavy  forged  bracket  connected  by  a 
pin  to  a  socket  at  the  center  of  the  axle.  A  chain  on  each  'side 
of  the  boiler  leading  to  each  of  the  front  wheels  and  operated  by 
the  engineer  directs  the  advance  and  turning  of  the.  machine. 
The  rear  end  of  the  boiler  with  the  fire-box,  ash-pit,  etc.,  is  directly 
supported  on  the  axle  of  the  two  large  driving-wheels.  The  tires 
of  these  wheels  are  very  wide,  and  are  provided  with  transverse 
ribs  to  grip  the  ground.  A  small  horizontal  engine  on  top  of 
the  boiler  engages  a  system  of  cog-wheels  which  cause  the  rear 


102  EARTH  AND  ROCK  EXCAVATION. 

wheels  of  the  machine  to  revolve,  thus  propelling  it.  The  same 
engine  by  means  of  beveled  wheels  and  shafts  imparts  motion  to 
the  upper  drum  of  the  carrier,  and  consequently  to  the  belt  con- 
veyor. 

Steel  brackets,  fixed  at  each  side  of  the  boiler  by  means  of 
chains,  support  both  the  plow  and  the  conveyor.  These  chains 
are  wound  around  shafts  regulated  by  the  engineer,  who  by  simply 
turning  a  sprocket-wheel  raises  them  and  moves  the  machine  as 
any  ordinary  road  locomotive,  or  by  lowering  both  the  plow  and 
the  conveyor  they  engage  the  soil  and  the  machine  then  works 
as  a  grader  and  ditcher.  The  plow  is  fixed  to  an  I  beam,  having 
in  front  a  small  wheel  so  as  to  direct  its  course,  and  the  I  beam  is 
suspended  to  the  longitudinal  shaft  by  means  of  two  chains,  and 
in  the  manner  indicated  in  the  illustration.  The  carrier  is  similar 
and  works  in  the  same  way  as  the  one  described  in  the  New  Era 
grader.  The  machine  is  regulated  by  one  engineer,  who  stands 
on  a  platform  at  the  rear  -end  of  the  boiler,  having  at  his  command 
all  the  wheels  for  the  various  movements  of  the  machine. 

The  happy  arrangement  of  the  heavy  boiler  and  mechanism 
at  the  center  of  the  machine,  with  its  working  parts  placed  on 
each  side  of  the  boiler,  makes  the  whole  a  very  solid,  compact, 
and  easily  handled  machine,  and  the  result  is  that  very  efficient 
work  is  obtained.  Besides,  such  an  arrangement  prevents  the 
staggering  of  the  machine,  a  defect  very  common  with  the  grader 
moved  by  animal  power.  For  this  reason,  and  also  on  account 
of  the  simplicity  of  direction,  which  is  in  the  hands  of  one  man, 
the  theoretical  work  of  the  automobile  grader  is  twice  as  much 
as  that  of  the  New  Era  grader,  and  experiments  made  at  Wacor 
Texas,  and  Philadelphia  fully  confirm  the  statements  of  the  manu- 
facturers. 

The  cost  of  the  automobile  steam  grader  and  ditcher  is 
only  $3000.  Its  operating  expenses  being  calculated  at  $18  per 
day,  the  cost  of  the  unit  of  volume  of  the  work  will  be  just  half 
of  that  given  for  the  New  Era  grader. 

Speaking  of  the  graders  and  ditchers,  it  is  necessary  to  men- 
tion a  grader  which,  although  it  cannot  be  considered  as  an 


EARTH  EXCAVATION:  MACHINE  EXCAVATION. 


103 


excavating-machine  according  to  the  definition  given,  is  yet 
an  essential  part  of  any  contractor's  plant.  This  grader,  or  lev- 
eler,  is  chiefly  used  for  finishing  >6nd  leveling  roads  and  to  prepare 
them  for  the  pavement;  but  in  some  cases  it  is  also  used  in  the 
excavation  of  small  trenches  and  canals  through  very  loose  soils. 
Fig.  44  illustrates  the  Western  steel  reversible  road-machine, 


FIG.  44. 

which  is  the  latest  grader  placed  on  the  market ;  similar  machines, 
however,  are  built  by  the  F.  C.  Austin  Mfg.  Co.,  Western  Wheeled 
Scraper  Company,  and  the  Stuart  Grader  Company  of  Oberlin,  Ohio. 
The  machine  consists  of  a  steel  frame  mounted  on  four  wheels; 
the  main  frame  is  provided  with  a  seat  in  front  for  the  driver 
and  a  platform  in  the  rear  for  the  operator.  The  front  wheels 
are  small,  so  that  the  machine  may  turn  on  a  small  circle.  Two 
iron  posts  fixed  at  the  middle  of  the  main  frame  support  a  beam, 
which  is  also  connected  with  the  frame  above  the  axle  of  the  front 
wheels.  The  beam  supports  a  floating  scraper-blade  which  is 
regulated  by  the  operator  by  means  of  chains  or  levels.  The 
scraper-blade  turns  on  a  disk  and  may  be  raised  or  lowered  and 


104  EARTH  AND  ROCK  EXCAVATION. 

assume  any  position,  so  that  it  may  excavate  a  ditch  of  any  dimen- 
sion and  to  a  depth  of  2J  ft.  The  earth  is  turned  over  one  side, 
and  when  the  machine  is  working  in  the  opposite  direction  the 
earth  is  turned  over  the  other  side,  thus  forming  the  ditches  and 
embankments  of  small  irrigat ing-canals.  It  is  in  this  kind  of 
work  that  the  machine  is  very  efficient  and  to  which  it  is  especially 
adapted.  The  axle  of  the  hind  wheels  can  be  quickly  extended  on 
either  side,  so  that  the  wheel  on  the  delivering  side  of  the  machine 
is  no  obstruction  to  the  discharge  of  the  earth  from  the  blade.  The 
shape  and  construction  of  the  scraper-blade,  as  well  as  the  manner 
of  regulating  the  machine  in  its  work,  form  the  claims  of  the  vari- 
ous patents  of  this  machine  as  manufactured  by  the  different 
manufacturers. 

The  force  required  to  operate  a  grader  consists  of  five  horses 
and  two  men,  and  the  operating  expenses  can  be  assumed  at 
$12  per  day.  The  efficiency  of  the  machine  depends  upon  the 
soil  and  character  of  the  work  it  performs.  Thus,  for  instance, 
in  leveling  roads  its  theoretical  efficiency  can  be  considered  at 
35,000  sq.  yds.,  and  in  excavating  trenches  through  very  light 
and  sandy  soil  as  1500  cu.  yds.  It  will  be  safe  to  assume  the  real 
working  efficiency  of  the  machine  at  only  one-half  these  figures. 


CHAPTER  IX. 
EARTH   EXCAVATION:    CONTINUOUS   DIGGING-MACHINES. 

EXCAVATING-MACHINES  which  also  automatically  discharge 
the  excavated  material  into  cars,  thus  performing  the  double 
purpose  of  excavating  and  loading  machines,  can  be  divided  into 
two  classes,  viz.,  continuous  excavators  and  intermittent  excava- 
tors. With  the  exception  of  trenching-machines,  several  of  which 
have  been  recently  put  on  the  market,  no  continuous  excavators 
are  used  in  America  and  England,  but  in  Continental  Europe 
they  find  great  favor  with  both  engineers  and  contractors.  In 
England  and  America  the  preferred  excavating-machine  is  the 
steam-shovel,  or  navvy. 

Continuous  excavators  for  land  use  are  constructed  on  the 
same  principle  as  the  ladder  dredge  for  marine  use.  They  con- 
sist of  two  endless  chains  stretched  between  and  passing  around 
two  revolving  drums,  and  provided  with  scoops  or  buckets,  which, 
being  held  against  the  ground-surface  and  given  motion  by  revolv- 
ing one  of  the  drums,  scrape  up  the  soil  and  discharge  it  into 
suitable  receptacles.  The  first  continuous  excavator  was  pat- 
ented in  1859  by  Mr.  Chevreux,  a  Frenchman,  and  was  used  on  the 
Suez  Canal.  Since  then  numerous  other  machines  of  this  type 
have  been  designed  and  placed  on  the  market.  In  some  of  these 
the  ladder  carrying  the  chain  of  buckets  is  placed  transversely 
of  the  car  and  in  others  it  is  placed  longitudinally,  or  parallel  to 
the  axis  of  the  car.  All  of  these  excavators  can,  however,  be 
classified  either  as  up-digging  or  down-digging  machines.  The 
distinguishing  features  of  these  two  forms  of  excavator  are  illus- 
trated by  Fig.  45.  The  down-digging  machine  is  located  on  the 
surface  being  excavated,  is  a  machine  of  large  dimensions  and 

105 


106  EARTH  AND  ROCK  EXCAVATION. 

great  power,  and  is  used  for  deep  excavations;    the  up-digging 
machine  stands  on  the  new  surface  formed  by  the  excavation,  is  of 


FIG.  45. 

smaller  dimensions  and  power,  and  is  used  either  on  shallow  cuts 
or  to  prepare  the  work  for  down-digging. 

Down-digging  Machines.—  To  illustrate  machines  of  the  down- 
digging  type  the  continuous  excavator  built  by  Henry  Satre  of 
Lyons,  France,  is  shown  in  Fig.  46.  This  is  one  of  the  most 
perfect  machines  of  the  type,  and  has  been  extensively  used 
in  Europe,  on  the  Panama  Canal,  and  elsewhere.  The  excavating 
mechanism  proper  is  located  on  a  steel  platform  supported  by  a 
double  truck  running  on  tracks  of  ordinary  gauge.  To  increase 
the  stability  of  the  machine  while  at  work  two  other  wheels  are 
inserted  on  the  excavation  side,  and  for  the  same  purpose  a  third 
rail  is  introduced,  and  the  axles  of  the  hind  wheel  of  the  front 
truck  and  that  of  the  front  wheels  of  the  hind  truck  are  made 
much  longer  in  order  to  receive  these  supplementary  wheels. 
The  machine  is  self-propelling  by  means  of  an  endless  chain  run- 
ning from  a  sprocket-wheel  on  the  crank-shaft  of  the  engine  to  a 
sprocket-wheel  on  the  front  axle  of  the  hind  truck. 

On  the  steel  platform  on  the  opposite  side  of  the  ladder  is  mounted 
a  re  turn -tubular  steam-boiler,  11.24  ft.  long  and  5  ft.  in  diameter, 
having  a  total  heating  surface  of  537  sq.  ft.  A  double-cylinder 
reversible  vertical  engine  of  55  H.P.  capacity  is  used.  This  by 
means  of  an  endless  chain  and  sprocket-wheel  moves  the  upper 
tumbler  of  the  ladder  fixed  to  a  frame  firmly  secured  to  the  plat- 


EARTH  EXCAVATION:  CONTINUOUS  DIGGING-MACHINES.     107 


FIG.  46. 


108  EARTH  AND  ROCK  EXCAVATION. 

form  of  the  car.  The  tumbler  is  composed  of  an  axle  with  two 
hexagonal  wheels,  each  side  of  the  hexagon  being  such  as  to 
perfectly  receive  the  links  of  the  articulated  chains  carrying 
these  buckets.  The  hexagonal  wheels  are  placed  3  ft.  apart,  thus 
leaving  a  free  space  into  which  the  buckets,  in  turning  over,  unload 
their  contents  into  a  hopper  and  through  a  chute  to  the  cars. 

The  ladder  is  made  of  two  trussed  iron  beams,  43.6  ft.  long, 
braced  together  and  provided  with  rollers  on  the  upper  side  so 
as  to  facilitate  the  running  of  the  chains.  It  is  fixed  to  the  frame 
of  the  tumbler  and  chute  by  means  of  two  heavy  turnbuckles, 
which  permit  regulating  the  tension  of  the  chains  carrying  the 
buckets.  To  insure  the  stability  of  the  machine  a  hollow  box  of 
5  tons  capacity  is  located  on  the  opposite  side  of  the  ladder  at 
the  level  of  the  tumbler.  At  the  lower  end  of  the  ladder  there 
are  two  flanged  sheaves  for  guiding  the  chains.  The  ladder  is 
hinged  at  its  upper  end  and  free  at  the  lower,  so  that  it  may  assume 
any  angle,  thus  closely  following  the  inclination  of  the  slope  of 
the  ground  to  be  excavated.  The  raising  and  lowering  of  the  ladder 
is  obtained  by  means  of  a  chain  regulated  by  a  single  reversible 
drum  and  a  system  of  sheaves,  the  most  important  being  the 
one  placed  on  top  of  a  framed  jib.  This  jib  consists  of  two  I-beams 
4  ft.  apart  and  braced  together  at  their  upper  and  lower  ends 
and  near  the  center,  thus  leaving  large  spaces  in  order  not  to 
interfere  with  the  ladder.  The  lower  end  of  this  jib  is  pivoted 
to  the  platform  of  the  car,  and  the  upper  end  is  braced  by  means 
of  iron  rods  to  the  frame  carrying  the  driving-tumbler. 

The  buckets  are  of  steel,  of  7.76  cu.  ft.  capacity.  They  are 
constructed  with  a  hemispherical  face  provided  with  a  sharp 
cutting  edge;  their  backs  are  flat  and  are  attached  to  the  links 
of  the  chains,  the  links  being  hung  at  the  back  of  the  buckets. 
When  the  ladder  is  lowered  down  in  contact  with  the  bank,  the 
buckets,  by  gradually  cutting  a  slice  all  the  way  up  the  bank,  become 
filled  and  carry  the  material  up  to  the  driving-tumbler.  When 
the  links  of  the  chains  attached  to  the  buckets  turn  over  the  tumbler 
the  material  will  fall  by  gravity  into  the  hopper  and  through  a 
chute  into  the  cars.  Twenty  buckets  turn  over  the  tumbler  every 


EARTH  EXCAVATION:  CONTINUOUS  DIGGING-MACHINES.      109 

minute,  so  that  the  theoretical  efficiency  of  this  machine  per  ten-hour 
day  will  be  7. 76X20x60x10*=  33, 120  cu.  ft.  or  3450.45  cu.  yds. 
Notwithstanding  that  the  experiments  made  at  Pantin,  France, 
have  given  actual  results  very  close  to  the  theoretical  efficiency 
of  the  machine,  its  real  work  depends  upon  many  circumstances, 
the  most  important  being  the  quality  of  the  soil  to  be  excavated 
and  the  manner  in  which  the  work  is  arranged.  In  the  excava- 
tion of  the  Panama  Canal  300  cars  of  6  cu.  yds.  each  is  the  average 
efficiency  of  the  Satre  excavator. 

As  a  rule  these  continuous  excavators  give  the  best  results  in 
sand,  soft  clay,  and  dirt;  and  their  efficiency  also  depends  upon 
the  arrangement  of  the  work.  They  require  in  particular  empty 
cars  always  at  hand  to  receive  the  excavated  materials.  Since 
the  buckets  must  continually  attack  a  new  surface,  the  machine 
has  to  be  moved  very  often,  and  it  is  thus  considered  more  con- 
venient to  place  the  machine  alongside  the  trench  to  be  excavated 
than  at  the  front,  since  it  will  then  have  to  travel  the  entire 
length  of  the  trench  before  it  returns  to  the  first  position,  thus 
allowing  all  the  time  necessary  for  the  arrangement  of  the 
tracks. 

This  machine  works  well  to  a  vertical  depth  of  20  ft.  It  is 
operated  by  an  engineer,  a  coalman,  a  fireman,  three  carmen,  and 
a  chainman,  and  its  consumption  of  coal  is  3  tons  per  day.  Con- 
sidering the  wages  of  the  engineer  at  $3  per  day  and  those  of  the 
other  men  at  $2  each,  and  the  cost  of  coal  at  $4  per  ton,  the  daily 
expenses  of  running  this  machine  will  be  $27  or  $0.008  per  cu.  yd. 
of  the  theoretical  capacity  and  $0.015  of  the  actual  capacity. 

In  the  excavation  for  the  improvement  of  river  shores  or 
canal  slopes  the  continuous  down-digging  machine  gives  the  best 
result.  Its  employment  is  also  very  convenient  in  the  excavation, 
of  wide  trenches  greatly  extending  in  length,  and  where  the  ex- 
cavated materials  are  deposited  on  wash-banks  away  from  the 
line  of  the  work.  But  it  is  not  at  its  best  in  working  trenches 
where  the  excavated  material  has  been  used  in  the  embankments 
for  the  construction  of  the  road-bed,  except  in  the  case  that  the 
excavated  earths  can  be  hauled  directly  from  the  top  of  the  trench 


110  EARTH  AND  ROCK  EXCAVATION. 

to  the  embankment  on  specially  built  temporary  roads  and  not 
along  the  newly  constructed  road-bed. 

Down-digging  machines  of  different  capacity  are  on  the  market ; 
they  vary  from  very  light  to  heavy  models.  In  selecting  one 
of  these  machines,  however,  it  will  be  better  to  choose  a  model 
of  medium  size;  a  too  light  machine  may  be  easily  overturned, 
while  one  that  is  too  heavy  is  difficult  to  transport  and  liable 
to  fall  down  the  bank  which  it  undermines.  It  must  be  remem- 
bered that  the  down-digging  machine,  Mr.  W.  P.  Williams  says, 
rests  on  the  edge  of  the  terrace  and  the  slope,  inclined  at  an  angle 
of  two  to  one,  is  not  flat  enough  to  prevent  a  sliding  tendency 
of  the  bank  caused  by  a  50-ton  weight  and  a  vibratory  movement 
from  the  contact  of  the  bucket  with  the  bank.  But,  on  the  other 
hand,  Mr.  A.  W.  Robinson  says  it  is  claimed  that,  as  they  stand 
on  top  of  the  bank  instead  of  in  the  bottom  of  the  pit,  they  have 
the  double  advantage  of  being  independent  of  seepage -water, 
and  of  requiring  less  locomotive  power  to  haul  away  the  loaded 
trains. 

Up-digging  Machine. — It  has  been  observed  in  down-digging 
machines  that  the  tendency  of  the  buckets  to  retain  their  con- 
tents is  inversely  proportioned  to  the  slope  of  the  bank.  The 
buckets  are  traveling  in  a  position  very  near  the  vertical  when 
the  slope  of  the  bank  is  very  small,  while  they  are  traveling 
nearly  horizontally  when  the  slope  is  very  inclined;  consequently 
the  buckets  are  in  the  most  favorable  position  and  perform  more 
efficient  work  when  the  bank  upon  which  the  machine  is  working 
has  small  inclination  and  when  it  is  most  liable  to  cave  in  under 
the  great  weight  and  strain  of  the  machine.  To  avoid  such  an 
accident  Messrs.  Jacquelin  &  Chevre  have  devised  a  machine  in 
which  the  buckets  travel  in  a  vertical  position,  assuming  the 
inclined  one  when  passing  over  a  tumbler  where  they  discharge 
their  content  into  a  hopper.  Fig.  47  represents  the  Jacquelin  & 
Chevre  continuous  excavator  as  modified  by  Mr.  Charles  Bourdon 
and  employed  in  the  excavation  of  the  Panama  Canal. 

The  machine  is  mounted  on  a  steel  turntable  resting  on  a 
strongly  framed  iron-and-steel  platform  car  supported  on  a  four- 


EARTH  EXCAVATION:  CONTINUOUS  DIGGING-MACHINES.     Ill 

wheeled  truck  which  runs  on  tracks  of  ordinary  gauge.  A  tubular 
boiler  is  placed  on  the  turntabje  at  the  rear  end  of  the  car,  its 
axis  being  transversally  to  the  longitudinal  axis  of  the  truck. 
It  is  arranged  in  this  way  in  order  to  be  in  equilibrium  with  the 


Elevation 


FIG.  47. 


ladder  and  buckets,  which  are  located  at  the  front  end  of  the 
machine.  A  vertical  engine  operating  the  machine  is  placed  at 
the  center  of  the  turntable.  The  engine  by  means  of  sprocket- 
wheels  and  chains  causes  the  rotation  of  the  upper  tumbler  of 
the  ladder,  thus  imparting  the  motive  power  to  the  excavating 
part  of  the  machine.  The  engine  causes  also  the  rotation  of  the 
turntable  around  its  axis  in  order  that  the  ladder  may  turn  on  a 
radius  and  be  brought  continuously  in  front  of  new  surfaces  of 
the  bank  to  be  excavated.  In  many  cases  the  engine  commands 
also  another  drum  guiding  the  belt  conveyor  upon  which  the 


112  EARTH  AND  ROCK  EXCAVATION. 

material  from  the  hopper  goes  to  the  rear  end  of  the  machine  and 
is  dumped  into  the  cars.  The  machine  is  not  self-propelling,  its 
movement  ahead  being  obtained  by  means  of  a  rope  which  is 
wound  around  the  winch-head  of  the  engine  and  passes  over  a 
sheave  fixed  to  a  post  strongly  located  in  the  ground  in  front  of 
the  machine. 

The  ladder  is  made  up  of  a  triangular  frame  fixed  to  the  turn- 
table by  means  of  iron  rods,  and  it  carries  four  drums.  Each 
section  of  the  ladder  is  composed  of  two  iron  beams  braced  together 
and  having  an  open  space  in  the  center  in  order  not  to  interfere 
with  the  travel  of  the  buckets.  Of  the  four  drums  carried  by  the 
ladder  only  one  is  operated  by  the  engine,  the  others  being  sim- 
ply used  to  guide  the  chains  carrying  the  buckets.  The  drums  are 
composed  of  an  axle  and  two  grooved  sheaves  of  polygonal  form, 
the  sides  of  the  polygon  being  made  in  such  a  way  as  to  give  full 
support  to  every  link  of  the  chain  when  they  pass  over. 

The  buckets,  instead  of  being  fixed  to  the  links  of  the  chains 
as  in  down-digging  machines,  are  simply  suspended  to  a  horizon- 
tal steel  axis.  The  bottom  of  the  buckets  is  provided  with  steel 
spurs  which  slide  upon  the  flanges  of  the  beams  on  the  excavating 
side  of  the  ladder,  thus  giving  a  stronger  support  to  the  buckets 
while  they  are  under  the  strain  of  tearing  the  earth  from  the 
bank.  The  capacity  of  the  buckets  is  2.24  cu.  ft.  The  velocity 
of  the  chain  is  0.984  ft.  per  second,  15  buckets  passing  over  the 
tumbler  every  minute.  The  theoretical  efficiency  of  this  machine 
per  ten  hours  is  2.24X  15X60X  10-20,160  cu.  ft.  or  746.66  cu.  yds. 

Up-digging  machines  can  easily  cut  banks  from  25  to  30  ft. 
high.  They  are  very  useful  in  the  excavation  of  trenches  for 
single-track  railroads,  in  which  all  the  cut  at  the  front  can  be  made 
on  a  single  advance.  Working  at  the  center  of  the  cut  when  the 
transportation  is  done  by  cars  running  on  narrow-gauge  tracks,  a 
single-track  line  can  be  placed  on  each  side  of  the  machine.  The 
excavated  materials  reaching  the  rear  of  the  machine,  traveling 
on  a  belt  conveyor,  fall  either  at  the  right  or  at  the  left,  thus 
loading  the  cars,  which  on  account  of  the  two  tracks  may  be 
always  at  hand.  In  such  a  condition  the  machine  may  work  con- 


EARTH  EXCAVATION:  CONTINUOUS  DIGGING-MACHINES.     113 

tinuously ;  the  only  time  lost  will  be  in  its  advance,  which,  however, 
takes  only  a  few  minutes,  and  its  actual  will  be  very  near  its 
theoretical  efficiency.  But  in  fSalculating  the  capacity  of  this 
machine  it  .will  be  convenient  to  assume  it  at  two-thirds  of  its 
theoretical  efficiency;  in  round  numbers  it  will  be  500  cu.  yds. 
per  ten  hours'  work. 

The  running  expenses  of  the  up-digging  machine  is  calculated 
at  $18  per  day,  and  the  cost  of  excavation  of  1  cu.  yd.  of  earth 
will  be  $0.024  based  on  its  theoretical  efficiency,  and  $0.032  based 
on  its  real  work.  The  weight  of  the  machine  is  thirty  tons,  and 
when  working  on  newly  excavated  ground  the  tracks  upon  which 
it  runs  must  be  strongly  timbered.  Up-digging  machines  are 
exclusively  used  by  Continental  contractors,  especially  in  Germany, 
but  do  not  find  any  favor  amongst  Americans  and  Englishmen. 

The  Austin-Trench  Excavating-machine. — Built  on  the  same 
principle  as  continuous  excavators,  there  is  a  small  machine  for 
the  excavation  of  narrow  trenches,  called  the  Austin  trench- 
excavating  machine  and  built  by  the  Municipal  Engineering  and 
Contracting  Company  of  Harvey,  111.  It  was  thus  described  in 
the  Engineering  News  of  Sept.  19,  1901 : 

The  machine  (Fig.  48)  consists  of  a  frame  built  up  mainly  of 
steel  I  beams  and  mounted  on  four  broad-tired  wheels.  Over 
the  front  axle  is  a  shaft  to  which  is  pivoted  a  frame  about  20  ft. 
long,  composed  of  two  steel  channels  connected  by  cross-pieces. 
The  shaft  at  the  head  of  the  machine,  to  which  this  frame  is 
pivoted,  and  another  shaft  at  the  outer  end  of  the  frame  are  each 
fitted  with  two  hexagonal  sprocket-wheels  carrying  a  pair  of  end- 
less link-belt  chains,  built  up  of  steel  drop-forged  links  connected 
by  cross-bars  and  flat  blades  or  scrapers.  Each  cross-bar  is  fitted 
with  two  or  three  cutters  of  drop-forged  steel,  the  cutters  on  the 
several  bars  being  staggered  so  that  the  entire  series  of  cutters 
will  cover  the  whole  width  of  the  excavation.  Alternate  bars 
are  also  fitted  with  side  cutters  or  reamers  for  trimming  the  sides 
of  the  trench  so  as  to  give  a  clearance  for  the  cutter-frame.  The 
blades  behind  the  cutters  form  scoops  to  carry  up  the  material 
removed  by  the  cutters. 


114 


EARTH  AND    ROCK    EXCAVATION. 


At  the  rear  end  of  the  machine  are  two  vertical  sliding  bars, 
the  lower  ends  of  which  are  attached  to  the  end  of  the  cutter-frame. 
The  bars  are  fitted  with  racks,  gearing  with  pinions  on  a  trans- 
verse shaft  above  the  rear  axle.  This  shaft  is  driven  by  gearing 
and  the  arrangement  constitutes  a  "crowding"  device  for  forcing 
the  cutter-frame  against  the  bottom  of  the  trench,  so  that  the 


FIG.  48. 

greater  part  of  the  weight  of  the  machine  is  carried  by  the  breast 
of  the  cut. 

The  depth  of  the  cut  is  regulated  by  raising  or  lowering  the 
free  end  of  the  cutter-frame.  The  cutters  travel  up  along  the  work- 
ing breast,  loosening  the  material  which  is  carried  up  by  the  blades 
or  scrapers.  At  the  head  of  the  machine  this  material  is  dumped 
upon  two  horizontal  belt  conveyors  at  right  angles  to  the  trench, 
which  discharge  the  excavated  material  either  into  wagons  for 
removal  or  upon  the  ground  alongside  the  trench  ready  for  the 
back-filling.  The  machine  hauls  itself  along  by  means  of  a  wire 
cable  anchored  about  300  ft.  ahead.  This  cable  is  wound  upon  a 
drum  which  has  at  one  end  a  ratchet  driving-wheel.  The  pawl 
of  this  wheel  is  operated  by  a  rod  from  an  eccentric  on  the  main 
shaft  of  the  machine,  and  the  throw  is  adjustable,  so  as  to  allow 


EARTH  EXCAVATION:  CONTINUOUS  DIGGING-MACHINES.     115 

of  regulating  the  speed  of  advance  or  feed  according  to  the  depth 
of  cut  and  the  character  of  th&  material. 

Power  is  derived  from  a  25-H.P.  traction  engine  coupled  ahead 
of  the  machine.  The  main  shaft  of  the  engine  carries  a  sprocket- 
wheel  connected  by  a  link-belt  driving-chain  with  a  similar  sprocket- 
wheel  on  the  main  shaft  of  the  excavating-maehine.  From  this 
latter  shaft  a  link  belt  drives  the  shaft  at  the  head  of  the  cutter 
frame,  while  vertical  link  belts  drive  the  bevel-gears  from  which 
the  conveyors  are  operated.  Two  men  are,  required  one  to  oper- 
ate the  traction  engine,  and  the  other  to  operate  the  excavator, 
stopping  and  starting  the  cutting  mechanism,  and  regulating  the 
speed  as  required.  Other  men  attend  to  the  hauling  cable,  the 
trench-sheeting,  and  the  back-filling. 

The  Austin  trench-excavating  machine  supplies  a  long-felt  want 
in  the  engineering  profession.  To  open  a  trench  for  pipes  or 
sewers,  when  the  work  is  done  by  hand,  often  requires  the  removal 
of  much  more  material  than  is  actually  needed  for  the  trench,  owing 
to  the  necessity  of  having  the  trench  wide  enough  for  the  men  to 
handle  their  tools.'  In  deep  trenches,  also,  the  work  by  hand 
labor  is  often  increased  by  the  necessity  of  working  in  stages,  the 
material  being  handled  two  or  three  times  before  it  reaches  the 
surface.  The  Austin  machine  does  the  work  cheaper  and  quicker 
than  by  hand.  It  has  already  been  used  on  contract  work  with 
success  in  different  kinds  of  soil.  At  Glencoe,  111.,  about  6,000  ft.  of 
trench  have  been  excavated  with  this  machine,  the  width  of  the 
trench  being  2  ft.  and  the  depth  from  9  to  15  ft.  The  material  was 
very  hard  stiff  clay.  The  2-ft.  trench  would  be  too  narrow  for  ex- 
cavation by  hand,  but  just  allows  room  for  the  pipe-layers  to  work, 
the  pipe  being  kept  up  to  within  about  15  ft.  of  the  machine. 
Behind  the  pipe-laying  the  back-filling  was  done  by  a  horse  and 
drag  scraper,  with  two  men;  the  scraper  working  across  the  trench 
and  scraping  the  excavated  material  from  the  ridges  into  the 
trench.  In  this  hard  material  the  excavator  dug  about  50  ft.  an 
hour,  but  in  good  earth  free  from  boulders  the  progress  may  be  as 
much  as  100  ft.  an  hour.  At  Glencoe  590  ft.  of  trench  13  to  15  ft. 
deep  were  excavated  in  a  working  day  of  ten  hours. 

Small  boulders  can  be  handled,  the  cutters  loosening  the  material 


116  EARTH  AND  ROCK  EXCAVATION. 

around  them  until  they  fall  out  and  are  carried  up  by  the  blades. 
For  large  boulders  the  cutter-frame  can  be  raised  and  the  stone 
removed  by  picks.  The  machine  will  work  in  any  place  where 
there  are  not  too  heavy  rocks  which  the  machine  cannot  handle. 
It  will  cut  trenches  24  to  48  ins.  wide  and  as  deep  as  20  ft. 

Still  another  machine  working  on  the  same  principle  as  the 
continuous  excavators  is  the  endless-chain  excavating-machine, 
used  in  the  excavation  of  the  tunnel  for  the  Central  London  Ry.  It 
represents  the  only  machine  that  has  ever  been  employed  in  the 
excavation  of  tunnels  through  loose  soils.  The  special  construc- 
tion of  the  ladder  and  the  buckets  travelling  horizontally  are  due 
to  the  particular  condition  of  the  work  this  machine  was  intended 
to  perform;  but  with  a  slight  modification  it  could  be  easily  made  a 
very  practical  trench-excavating  machine.  It  is  also  very  inter- 
esting on  account  of  being  the  first  excavator  run  by  electricity. 
The  description  and  cut  (Fig.  49)  of  this  machine  are  taken  from 
the  Engineering  News. 


FIG.  49. 

This  excavating-machine  consists  of  an  under-carriage  with 
wheels  running  on  a  6  ft.  3  in.  gauge  track.  This  carriage  has  an 
opening  beneath  5  ft.  8  ins.  high  and  sufficiently  wide  to  admit 
the  usual  2  ft.  gauge  cars  underneath  it.  The  top  of  this  carriage 
is  strongly  braced  and  carries  a  short  king-post  on  which  an  upper 
carriage  revolves.  This  upper  carriage  has  sides  of  plate-iron, 
cross-braced  and  with  a  central  casting  revolving  on  the  king-post; 
attached  to  the  top  of  this  carriage  is  an  endless  chain  carrying 
excavating-buckets.  The  frame  which  carries  this  chain  is  17  ft. 
long  and  is  held  up  by  two  chains  passing  to  a  winding-drum  in  the 
tipper  part  of  the  carriage. 


EARTH  EXCAVATION:  CONTINUOUS  DIGGING-MACHINES.     117 

The  machine  is  driven  electrically  by  a  100-ampere  motor  tak- 
ing current  at  200  volts.  Th%  current  is  supplied  by  a  20-H.P. 
engine  and  dynamo  atlhe  head-house.  The  motor  is  mounted  on 
the  back  end  of  the  carriage  and  drives  a  shaft  parallel  to  the  car- 
riage by  a  two-thread  worm  and  worm-wheel.  This  shaft  also 
operates  the  revolving,  the  propelling,  and  the  raising  and  lowering 
gear  by  suitable  bevel  pinions  and  wheels.  The  revolving-gear 
consists  of  a  pair  of  friction-cones  and  bevel-wheels  driving  through 
&  worm-gear,  a  chain-pulley  with  chains  passing  to  the  sides  of 
the  under-frame.  The  raising  and  lowering  of  the  bucket-ladder 
is  also  performed  by  a  pair  of  friction-cones  and  a  worm-gear, 
and  on  the  barrel  of  the  latter  the  lifting-chains  are  wound.  The 
traveling  gear  is  worked  from  a  pulley  on  the  opposite  end  of  the 
motor  and  belted  to  a  pulley  on  a  shaft  over  the  king-post.  From 
this  latter  shaft,  by  means  again  of  friction-cones,  another  shaft 
leading  down  the  king-post  is  operated,  and  drives,  by  a  worm- 
gear,  two  spools  placed  on  either  side  of  the  under-frame.  From 
these  spools  wire  ropes  are  led  and  anchored  to  the  sides  of  the 
tunnel,  and  by  them  the  machine  is  moved. 

As  the  excavat ing-buckets  are  run  at  higher  speeds  than  those 
used  on  dredges,  especial  care  has  to  be  given  to  the  feed,  and 
all  levers  and  wheels  for  the  control  of  the  machine  are  within 
easy  reach  of  the  operator,  who  stands  on  a  small  platform  on 
the  left  of  the  machine.  The  bucket-ladder  is  fitted  with  a  screw 
extension  device  for  tightening  up  the  bucket-chain.  The  buckets 
are  really  scrapers  and  each  has  four  or  five  teeth,  placed  alter- 
nately, chisel-shaped  and  fitting  into  recesses  cast  in  the  back  of  the 
buckets ;  but  as  one  or  two  were  broken,  gun-metal  has  since  been 
employed  with  better  results. 

While  the  machine  is  not  as  large  or  heavy  as  experience  shows 
would  be  desirable,  the  only  stoppages  have  been  due  to  the  break- 
ing of  buckets.  As  it  is,  the  saving  over  hand  labor  is  very  con- 
siderable and  an  average  advance  of  three  20-in.  rings  is  made  in 
ten  hours  with  eight  men  at  the  face,  including  the  machine 
operator. 


CHAPTER   X. 
EARTH  EXCAVATION:    INTERMITTENT  DIGGING-MACHINES. 

LIKE  continuous  excavators,  those  which  operate  intermittently 
may  be  divided  into  two  classes,  those  which  excavate  upward 
and  those  which  excavate  downward.  Steam-shovels,  or  navvies 
as  they  are  called  in  England,  are  up-digging  machines  and  orange- 
peel  and  clam-shell  excavators  are  down-digging  machines.  Each 
of  these  types  of  excavators  will  be  discussed  by  itself. 

Steam-shovels.  —  If  we  observe  the  movements  of  a  man 
shoveling  it  will  be  seen  that  they  are  as  follows:  (1)  The  shovel 
is  lowered;  (2)  the  blade  is  thrust  into  the  ground;  (3)  the  filled 
shovel  is  raised;  and  (4)  the  shovel  is  swung  around  to  discharge 
its  load  into  the  waiting  wagon  or  car.  All  these  movements 
are  exactly  reproduced  by  the  steam-shovel.  The  shovel  proper 
consists  of  a  large  bucket  or  dipper  attached  to  a  dipper-handle 
supported  by  a  boom  or  jib  which  can  slew  around  a  full  semi- 
circle or  more.  It  is  operated,  through  a  system  of  chains  and 
sheaves,  by  a  three-drum  reversible  engine  located  on  a  car  which 
also  carries  the  steam-boiler  and  all  other  operating  machinery. 
Steam-shovels  are  self-propelling  and  are  operated  by  an  engineman 
and  a  craneman.  The  movements  of  a  steam-shovel  in  operation 
are  as  follows:  (1)  The  dipper  is  lowered  to  the  ground;  (2)  its 
edge  is  thrust  into  the  bank;  (3)  the  dipper  is  then  raised  so  as 
to  scrape  or  scoop  out  the  bank  until  full;  and  (4)  the  dipper  is 
swung  around  over  the  car  and  its  contents  discharged  by  unhitch- 
ing the  bottom,  which  swings  open  on  a  hinge.  The  lowering  of 
the  bucket  is  accomplished  by  loosening  the  hoisting-chain,  which 
passes  over  the  top  of  the  boom  and  supports  the  pulley  to  which 
the  dipper  is  attached.  The  second  movement  is  obtained  by 

118 


EARTH  EXCAVATION:  INTERMITTENT  DIGGING-MACHINES.   119 

lengthening  the  dipper-handle;  this  is  done  by  the  craneman, 
who  stands  at  the  foot  of  the"  boom.  By  means  of  a  foot-break 
he  can  arrest  the  dipper-handle  in  any  position,  thus  having  a 
point  of  support  around  which  it  may  rotate.  The  raising  of 
the  dipper  is  accomplished  by  reversing  the  drum  of  the  hoisting- 
chain;  the  bucket  scraping  the  earth  is  filled  with  dirt.  Then 
the  craneman  loses  a  little  the  foot-break,  and  withdraws  the 
dipper-handle  so  as  to  disengage  the  bucket  from  the  material. 
The  slewing  of  the  boom  or  jib  is  accomplished  by  a  chain  encased 
horizontally  in  a  groove  of  a  large  wheel  at  the  foot  of  the  boom. 
In  turning,  the  bucket  reaches  a  position  just  above  the  car  to 
be  loaded;  the  craneman  then  pulls  a  rope  commanding  a  latch 
at  the  bottom  of  the  bucket,  which  is  thus  opened  and  the  earth 
falls  by  gravity  into  the  car  below.  The  bottom  of  the  bucket 
closes  automatically  when  the  dipper  is  brought  back  against  the 
earth  to  be  excavated. 

According  to  Mr.  Hermann,  the  first  steam-shovel  was  designed 
and  patented  by  Mr.  Otis  about  1840,  but  it  was  not  until  1865 
that  the  machine  came  into  general  use.  It  is  now  built  by 
several  manufacturers,  whose  machines  vary  in  the  design  of 
various  parts,  but  the  principles  of  operation  are  essentially  the 
same  in  them  all.  Only  two  models  of  steam-shovels  will  be 
illustrated  here,  the  Earnhardt  steam-shovel,  built  by  the  Marion 
Steam-shovel  Company  of  Marion,  Ohio,  and  the  Dunbar-Ruston 
steam-navvy,  built  by  Huston  Proctor  &  Co.,  Ltd.,  of  Lincoln, 
England. 

Earnhardt  Shovel. — The  Earnhardt  steam-shovel,  illustrated 
by  Fig.  50,  is  mounted  on  a  platform  car  supported  on  two  four- 
wheel  trucks  of  the  usual  construction  and  ordinary  gauge.  The 
bolster  and  cross-ties  of  the  car-frame  are  of  white  oak  reinforced 
by  steel  channels.  The  sills  are  of  steel  channels  and  I  beams, 
with  wood  filling,  securely  bolted  together  and  riveted  to  heavy 
steel  end  plates.  The  car  is  provided  with  a  draw-bar  at  each 
end  allowing  it  to  be  coupled  into  freight  trains  and  hauled  at 
ordinary  freight  speed.  To  prevent  the  car  from  tipping  under 
the  great  strain  of  the  shovel,  the  base  of  the  car  is  greatly  in- 


120 


EARTH    AND    ROCK    EXCAVATION, 


creased  by  means  of  two  steel  jack-braces  attached  one  on  each 
side  of  the  front  end  of  the  car.  The  jacks  being  hinged  are  easily 
folded  alongside  of  the  car  in  passing  obstructions  when  the  whole 
machine  is  in  movement. 

Both  the  boiler  and  the  engines  are  located  on  the  platform 
of  the  car,  the  boiler  being  at  the  rear  end,  the  engines  near 
the  center  of  the  car;  they  are  protected  by  timber  side  walls 
and  corrugated  iron  roof.  The  size  of  the  boiler  and  engines  varies 
with  the  various  models,  but  in  the  model  G,  here  illustrated,. 


FIG.  50. 

the  boiler  is  of  locomotive  type,  54  ins.  in  diameter;  the  fire-box 
being  48  ins.  long,  48  ins.  wide,  and  54  ins.  high.  It  contains 
70  flues  3  ins.  in  diameter,  each  72  ins.  long. 

Two  double-cylinder  vertical  engines  are  employed.  The 
one  used  for  hoisting  has  cylinders  10 X 12  ins.,  and  the  other,  used 
for  thrusting,  has  cylinders  7X8  ins.  The  drum-shaft  rotates 
continuously  in  one  direction.  On  it  there  is  mounted  a  heavy 
steel  gear,  driven  by  steel  pinion  on  the  engine-shaft.  Three 
friction-drums  are  also  mounted  on  this  shaft,  the  hoisting-drum 
in  the  center  and  the  swinging-drums  on  the  ends. 

In  front  of  the  covered  car  there  is  a  turntable  with  grooved 
flanges  to  encase  the  slewing-chain  of  the  boom.  The  turntable 
is  thoroughly  braced  and  stayed  in  every  direction  by  means 


EARTH  EXCAVATION:  INTERMITTENT  DIGGING-MACHINES.    121 

of  steel  plates,  bars,  and  forgings,  securely  riveted  together.  At 
the  center  of  the  turntable  fcis-  fixed  the  foot  of  the  boom,  which 
may  turn  by  turning  in  opposite  directions  the  two  drums  com- 
manding the  slewing^chain.  The  boom  is  an  inclined  oak  beam 
reinforced  by  steel  plates,  bars,  and  forgings,  with  a  slot  in  the  center; 
its  lower  end  is  fixed  to  the  turntable  and  its  upper  end  is  tied, 
by  means  of  an  iron  rod  with  turnbuckle,  to  a  pin  inserted  at  the 
top  of  the  A-frame  structure.  This  consists  of  two  racking-beams 
made  up  of  heavy  steel  bars  and  forgings,  with  filling  of  white 
cak,  surmounted  by  a  cast-steel  headpiece  and  in  the  shape  of 
the  letter  A.  The  A  frame  is  connected  at  the  bottom  with 
pedestals  by  means  of  heavy  forged-steel  hinges,  extending  through 
to  the  under  side  of  the  sills  of  the  car,  and  it  is  also  braced  to  the 
rear  end  of  the  car. 

The  boom  commands  the  shovel,  consisting  of  a  large  bucket 
and  the  dipper-handle.  The  latter  is  made  up  of  a  square  oak 
beam  reinforced  by  steel  plates,  bars,  and  forgings.  Its  lower  side 
is  provided  with  a  rack  engaging  a  system  of  cog-wheels  which  are, 
in  the  latest  models,  moved  by  a  small  engine  mounted  on  the 
boom.  Such  an  arrangement  permits  the  lengthening  and  short- 
ening of  the  handle,  and  by  a  break  it  may  be  arrested  in  any 
position,  thus  having  an  axis  around  which  it  rotates. 

The  bucket  or  dipper  is  of  2J  cu.  yds.  capacity.  It  is  of  plate- 
steel,  with  a  semi-elliptical  cross-section.  Its  cutting  edge  is 
armored  with  four  heavy  forged-steel  teeth  running  to  the  bottom 
of  the  bucket.  They  are  fastened  by  iron  bars  and  bolted  to  the 
bucket  with  flat-headed  bolts,  so  that  they  can  be  easily  removed 
and  changed  when  damaged.  The  bottom  of  the  bucket  or  dip- 
per is  made  of  steel  plate  and  is  hinged  at  one  side  and  kept  closed 
by  means  of  a  spring-latch.  The  bucket  is  provided  with  two 
racks,  one  near  the  top,  and  is  attached  to  a  sheave  suspended 
to  the  hoisting-chain;  the  other  rack  is  placed  near  the  bottom 
and  is  fixed  to  the  handle. 

This  machine  can  excavate  and  load  two  buckets  every  minute, 
and  consequently  its  theoretical  efficiency  is  5X60  X 100=  3000  cu. 
yds.  On  account  of  the  difficulty  of  coordinating  the  work  of 


122 


EARTH   AND    ROCK   EXCAVATION. 


two  or  three  operators  and  the  loss  of  time  in  advancing  the 
machine,  clearing  the  tracks,  waiting  for  the  cars,  and  other 
obstacles  which  are  met  with  in  the  excavation,  it  is  safe  to  con- 
sider the  real  practical  work  of  this  machine  not  more  than  one- 
half  of  its  technical  capacity,  and  usually  about  one-third.  The 
running  expenses  of  this  machine  can  be  assumed  at  $24,  divided 
into  the  following  items :  Two  engineers  at  $3  each ;  one  craneman 
and  one  fireman  at  $2;  six  carmen  at  $1.50;  1  ton  of  coal  at  $4;  and 
$1  for  oil,  water,  waste,  etc.  The  cost  of  excavating  1  cu.  yd.  of 
earth  with  this  machine  will  be  0.8  cent  at  full  capacity,  1 . 6  cents 
at  one-half  capacity,  and  2.4  cents  at  one-third  capacity. 

Dunbar  &  Ruston  Navvy. — The  steam-navvy  used  in  England 
is  much  similar  to  the  steam-shovel.     Fig.  51  illustrates  the  Dun- 


FIG.  51. 

bar  &  Ruston  steam-navvy  as  used  in  the  excavation  of  the 
Panama  Canal.  It  consists  of  a  strong  rectangular  wrought-iron 
frame  mounted  on  wheels,  forming  a  substantial  base  to  which 
all  the  parts  are  secured.  At  each  corner  of  the  frame  is  a  strong 
jack-screw,  and  a  fifth  is  placed  immediately  under  the  pivot  of 
the  jib  on  the  front  end  of  the  frame.  These  take  the  entire 
weight  when  at  work. 

On  the  back  end  of  the  frame  is  located  the  engine  beside 


EARTH  EXCAVATION:  INTERMITTENT  DIGGING- MACHINES.    123 

which  the  driver  stands.  The  engine  is  of  the  ordinary  vertical 
type,  with  a  cross-tube  boiler  carrying  usually  80  Ibs.  pressure, 
and  has  a  pair  of  cylinders  of  *!0  H.P.  nominal.  It  runs  up  to 
160  to  170  revolutions  per  minute  under  the  control  of  a  governor. 
On  the  crank-shaft  is  keyed  a  pinion,  gearing  into  a  spur-wheel 
four  times  its  size  on  the  main  drum-shaft,  from  which  all  the 
other  motions  are  transmitted. 

At  the  front  end  rises  a  wrought-iron  tower  carrying  the  top 
pivot  of  a  crane -jib,  the  lower  pivot  resting  on  girders  fixed  to 
the  main  frame.  The  tower  is  an  oblique  truncated  pyramid, 
well  extended  at  the  base  for  bolting  to  the  longitudinals  of  the 
main  frame.  It  is  formed  of  the  plate  sides,  stiffened  with  T 
irons,  and  braced  together  with  cross-plates  and  stays.  Between 
the  plates  is  an  opening  large  enough  for  the  driver  to  watch  the 
motion  of  the  bucket,  even  when  the  jib  is  straight  ahead.  The 
top  of  the  pyramid  is  finished  with  a  roof-plate  extended  forwards 
in  front  for  taking  the  top  pivot  of  the  jib,  and  stiffened  by  a 
V-shaped  girder  like  that  for  the  bottom  pivot;  on  this  table 
are  placed  also  the  guide-pulleys  for  the  main  chain. 

The  jib  may  be  said  to  be  of  twin  construction,  being  composed 
of  two  sides  which  are  united  only  at  the  post  and  at  the  outer 
end  or  point;  between  them,  therefore,  is  a  long  slot  in  which 
swings  an  arm  of  adjustable  length,  depending  from  a  fulcrum 
fixed  on  the  upper  member  of  the  jib.  At  the  base  of  the  post 
is  a  circular  platform,  on  which  a  man  stands  to  regulate  by  means 
of  a  hand- wheel  the  " reach"  or  length  of  radius  of  the  arm. 

The  bucket-arm  is  made  of  two  oak  planks  bolted  together  at 
top  and  bottom  so  as  to  leave  a  long  slot  between  them,  through 
which  passes  the  main  chain.  On  the  back  edge  of  each  plank  is 
a  rack,  gearing  with  a  pinion  fixed  on  the  fulcrum-shaft  on  the 
top  of  the  jib.  The  same  shaft  also  carries  a  swing-frame  pro- 
vided with  four  rollers,  which  press  on  iron  bars  or  runners  fixed 
along  the  front  edge  of  the  arm  so  as  to  hold  it  up  close  to  the 
fulcrum  while  yet  allowing  it  to  be  moved  longitudinally  by  the 
racks  and  pinions  for  lengthening  or  shortening  it ;  the  movement 
is  given  by  a  pitch-chain  wheel  on  the  outer  end  of  the  fulcrum- 


124  EARTH  AND  ROCK  EXCAVATION. 

shaft,  driven  from  a  pinion  on  the  hand-wheel  shaft,  which  is 
under  the  control  of  the  wheelman. 

The  bucket  is  made  of  steel  plate ;  its  mouth  is  semi-elliptical,, 
and  its  cutting  edge  is  protected  by  four  strong  picks  or  teeth, 
which  are  made  so  as  to  be  easily  renewed  when  worn,  being  fixed 
to  the  lip  of  the  bucket  by  countersunk  bolts  and  nuts.  On  the 
top  of  the  bucket  are  fixed  two  plates  strongly  gusseted,  between 
which  the  lower  end  of  the  arm  is  secured  by  a  through-pin.  The 
two  top  plates  carry  the  L-shaped  hinges  riveted  to  the  flap  or 
door.  This  is  fastened  by  a  stout  bolt  fixed  on  the  outside,  oppo- 
site to  the  hinges,  and  kept  closed  by  a  spiral  spring  protected  by 
a  casing.  By  pulling  a  cord  attached  to  the  bolt  this  is  with- 
drawn out  of  its  socket  and  the  door  falls  open  by  its  own  weight, 
and  hangs  vertically.  When  the  bucket  is  lowered  and  brought 
back  again  to  the  bank  the  door  latches  itself  automatically  in- 
closing. The  handle  or  "bale "  of  the  bucket  swings  on  pins  fixed 
about  centrally  on  each  side;  it  is  well  arched  to  allow  room  for 
the  dirt,  and  is  secured  to  the  snatch-block  by  a  pin  and  strap. 

The  main  lifting-chain  passes  from  the  winding-drum  of  the 
engine,  through  the  tower  and  over  the  pulleys  on  the  top,  through 
the  bucket-arm,  over  a  sheave  on  the  end  of  the  jib,  round  a 
snatch-block  on  the  handle  of  the  bucket,  up  to  another  sheave 
on  the  jib,  and  down  again  to  the  snatch-block,  obtaining,  there- 
fore, a  treble  purchase. 

The  capacity  of  the  bucket  in  the  machine  employed  on  the 
Panama  Canal  is  1J  cu.  yds.  It  takes  three-quarters  of  a  minute 
to  load  and  discharge  the  bucket  and  return  it  to  its  former  posi- 
tion. Moving  forward,  laying  rails,  and  waiting  for  cars  may  be 
set  down  as  a  deduction  of  10  minutes  per  hour,  leaving  50  minutes 
for  cutting,  which  gives,  say,  60  as  the  number  of  bucket-loads  per 
hour,  or  600  per  day  of  10  hours.  The  theoretical  capacity  of  this 
machine  can  therefore  be  assumed  at  750  cu.  yds.  per  day.  In 
practical  work,  however,  only  two-thirds  of  its  theoretical  effi- 
ciency is  obtained,  and  it  is  safe  to  calculate  its  output  at  500  cu. 
yds.  per  day. 

The  working  expenses  of  this  machine  can  be  calculated  at 


EARTH  EXCAVATION:  INTERMITTENT  DIGGING-MACHINES.    125 

$17.50,  divided  into  the  following  items:  One  engineer  at  S3,  a 
craneman  and  a  foreman  at  $2  each,  four  men  at  $1.50,  one  ton  of 
coal,  and  50  cents  for  water,  oilfand  waste.  The  cost  of  removing 
a  cubic  yard  of  earth  at  its  theoretical  efficiency  will  be  2.32  cents, 
and  at  its  practical  efficiency,  3.5  cents. 

Thew  Automatic  Steam-shovel. — From  the  description  of  the 
two  machines  given  above,  it  can  be  easily  seen  that  no  essential 


FIG.  52. 

difference  in  design  exists  between  the  American  steam-shovel  and 
the  English  navvy;  but  a  somewhat  radical  departure  in  the 
design  of  steam-shovels  was  taken  by  the  Thew  Automatic  Shovel 
Company  of  Lorain,  Ohio,  whose  shovel,  Fig.  52,  is  thus  illustrated 
by  the  Engineering  News,  Vol.  XLV,  p.  260.  The  chief  feature  of 
novelty  in  the  machine  is  found  in  the  construction  of  the  swinging 


126  EARTH  AND  ROCK  EXCAVATION. 

boom  and  the  method  of  manipulating  the  dipper,  particularly 
with  reference  to  the  crowding  motion.  The  dipper-arm  is  hinged 
to  a  carriage  or  trolley  which  slides  horizontally  along  a  trackway, 
forming  part  of  the  boom  structure.  The  dipper  is  forced  into 
the  material  to  be  excavated  by  advancing  this  carriage,  thereby 
shifting  the  point  of  rotation  for  the  dipper.  This  sliding  carriage 
is  of  steel,  with  replaceable  friction-shoes,  and  is  actuated  by  wire 
cables  operating  over  drums  geared  to  the  boom  engine.  Proper 
tension  for  the  cables  is  secured  by  adjustment  at  the  drums,  which 
are  double,  one  part  being  keyed  to  the  shaft,  the  other  loose  with 
suitable  provision  for  clamping  to  the  fixed  portion  when  in  desired 
position.  A  throttle-lever,  manipulated  by  the  craneman,  controls 
the  movement  of  the  trolley,  a  trip  at  each  end  of  the  horizontal 
stroke  cutting  off  the  steam  automatically  and  obviating  any  danger 
frcm  carelessness  on  the  part  of  the  operator. 

The  dipper-arm  is  of  rectangular  cross-section  and  adjustable  as 
to  the  length,  the  lower  portion  telescoping  into  the  upper  and 
being  held  in  place  by  a  lock  which  engages  the  teeth  of  a  rack 
attached  to  the  lowrer  member.  This  lock  is  retained  in  position 
by  a  spring  and  is  operated  by  means  of  a  lever  conveniently 
accessible  from  the  craneman's  platform.  The  lock  being  released, 
the  length  of  arm  can  be  adjusted  by  moving  the  trolley  back  or 
forward  as  desired. 

The  combination  of  the  boom  with  the  trolley  trackway  is 
claimed  to  afford  a  very  stiff  construction,  the  slight  clearance 
required  for  the  upper  end  of  dipper-arm  enabling  the  rigid  cross 
connection  of  the  two  sides  at  frequent  intervals.  The  boom 
girder  is  reinforced  by  Z  bars,  which  form  a  guide  for  the  dipper- 
handle,  thereby  greatly  increasing  the  lateral  rigidity  in  operation. 

The  boom  is  suspended  from  the  A-frame  head  by  wire  guy, 
cables.  A  further  departure  from  generally  accepted  methods 
is  found  in  the  use  of  wire  cables  instead  of  chains  for  the  hoisting 
and  swinging  motions.  With  sheaves  of  proper  diameter  it  is 
claimed  that  most  satisfactory  results  are  secured,  the  decrease  in 
friction  and  in  the  weight  of  operating  parts  being  of  considerable 
importance.  Additional  advantages  which  are  claimed  are  the 


EARTH  EXCAVATION:  INTERMITTENT  DIGGING-MACHINES.   127 

noiselessness  of  operation  and  the  lessening  of  unexpected  breakage, 
wire  cable  in  almost  every  instance  giving  ample  warning  of 
failure  by  its  exterior  appearance. 

In  general  construction  the  excavator  is  of  the  A-frame  type, 
with  independent  reversing-engines  for  the  hoisting,  swinging, 
and  crowding  motions.  Particular  attention  has  been  paid  to  the 
design  of  the  car  body,  especially  with  reference  to  the  rigid  con- 
nection of  the  front  portion  of  the  car  frame,  which  carries  the 
turntable,  boom,  A  frame,  and  jack-stays,  and  which  must  with- 
stand the  severest  strains  of  operation. 

The  practical  value  of  this  new  steam-shovel  has  been  fully 
demonstrated  not  only  in  the  excavator  just  described,  but  also 
in  single-truck  shovels  of  smaller  capacity,  of  which  a  large  number 
are  now  in  use  for  hauling  ore,  limestone,  and  fuel  in  blast-furnace- 
yards,  and  on  the  docks  at  Lake  Erie  ports,  as  well  as  in  placer 
mining  and  general  excavating  work. 

"'The  steam-shovel,  or  navvy,"  Mr.  Ruston  says,  "excavates 
and  delivers  into  wagons  any  material  capable  of  being  cut,  such 
as  sand,  gravel,  chalk,  and  clays  of  all  kinds,  digging  out  with  equal 
facility  the  hardest  and  toughest,  such  as  require  blasting  when 
worked  by  hand.  It  can  also  deal  with  these  materials  when 
thickly  interspersed  with  stones  and  heavy  boulders;  and  without 
being  unduly  strained  it  cuts  through  seams  of  flint,  shale,  slate, 
or  even  sandstone,  which  may  intersect  the  face  of  the  excavation 
it  is  at  work  upon." 

The  cutting  edge  of  the  bucket  is  never  at  a  height  greater 
than  14  ft.  from  the  ground,  but  the  steam- shovel  may  cut  faces 
of  much  greater  heights  because  it  undermines  the  bank,  thus 
causing  the  fall  of  the  upper  part,  which  then  may  be  easily  taken 
up  by  the  bucket ;  or  the  fall  of  the  upper  part  of  the  bank  may 
be  obtained  by  workmen  working  with  levers  and  crowbars,  and 
when  the  earth  is  at  the  foot  of  the  bank  it  can  be  picked  up  by  the 
bucket.  Consequently  the  machine  can  cut  banks  of  20  and  25  ft. 
and  even  greater  heights,  this,  however,  chiefly  depending  upon  the 
looseness  of  the  soil. 

The   steam-shovel  cuts  its  own  way  and  is  a  very  valuable 


128  EARTH  AND  ROCK  EXCAVATION. 

machine  in  cutting  for  single-track  roads  when  both  sides  may  be 
reached  on  a  single  advance.  Its  efficiency,  as  in  the  continuous 
up-diggers,  depends  mainly  upon  the  arrangement  of  the  transporta- 
tion service ;  it  is  greater  when  two  tracks  can  be  provided,  one  on 
each  side,  in  order  to  have  always  empty  cars  on  hand  and  ready  to 
be  filled.  But  it  also  does  very  efficient  work  in  excavating  large 
trenches;  then  the  transportation  will  be  done  by  one  track,  as 
will  be  seen  in  a  succeeding  chapter. 

In  regard  to  the  efficiency  of  the  steam-shovel  Mr.  A.  W. 
Robinson,  in  the  March,  1903,  number  of  the  Engineering  Maga- 
zine, describing  a  steam-shovel  of  his  own  design  and  built  by  the 
Bucyrus  Company  of  Milwaukee,  Wis.,  says:  "The  steam-shovel 
handles  a  dipper  of  3J  cu.  yds.  capacity  four  times  a  minute,  so 
that  in  a  good  bank  when  it  can  fill  its  dipper  the  rate  of  work 
is  14  cu.  yds.  per  minute.  It  can  make  a  cut  55  ft.  wide  and 
dump  its  load  16  ft.  above  the  rail.  It  is  worked  by  a  crew  of 
three  men  on  the  machine  and  two  to  five  laborers  in  the  pit, 
and  the  coal  consumption  is  about  H  tons  per  10  hours.  This 
shovel  has  a  record  of  5880  cu.  yds.  of  gravel  loaded  on  cars  in 
12  hours  and  45,000  cu.  yds.  in  9  days. 

To  make  the  great  capacity  of  this  shovel  available  it  is  neces- 
sary to  provide  car  service  of  large  capacity  and  as  nearly  con- 
tinuous as  possible.  Trains  of  twenty-five  cars,  each  holding 
twenty  or  more  cubic  yards,  and  hauled  by  powerful  locomotives, 
were  used  and  served  past  the  shovel  on  a  through  track,  and 
as  soon  as  one  was  loaded  its  place  was  taken  by  a  second 
train. 

From  this  it  can  be  deduced  that  notwithstanding  its  machine 
was  working  under  the  most  favorable  conditions,  yet  the  maxi- 
mum working  capacity  was  only  half  of  its  technical  efficiency, 
and  consequently  in  order  to  be  on  the  safe  side  it  is  necessary 
to  consider  the  work  of  the  machine  at  one-half  of  its  technical 
efficiency.  Besides,  the  working  capacity  chiefly  depends  upon 
the  arrangement  of  the  trains  which  are  hauling  away  the  excavated 
materials,  and  in  fact  it  will  be  useless  to  have  a  powerful  and 
expensive  machine  of  large  capacity  when  it  must  remain  idle 


EARTH  EXCAVATION:  INTERMITTENT  DIGGING-MACHINES.    129 

most  of  the  time  waiting  for  the  cars  to  haul  away  the  excavated 
materials. 

Land-dredges. — The  second  class  of  intermittent  excavating 
machines  comprises  all  those  which  dig  downward,  the  excavator 
standing  on  the  top  of  the  bank  being  excavated.  The  machine 
consists  essentially  of  a  derrick  or  crane  from  which  the  bucket 
is  suspended  and  raised  or  lowered  in  the  usual  manner.  This 
bucket  is  provided  with  an  arrangement  by  which  it  can  be  closed 
or  opened  at  will.  In  operation  it  is  lowered  open  to  the  ground, 
into  which  it  sinks  by  its  own  weight;  it  is  then  closed,  thus 
grabbing  a  quantity  of  earth,  raised,  and  swung  over  the  car, 
into  which  the  material  is  discharged  by  opening  the  bucket. 
Excavators  of  this  sort  are  successfully  employed  in  excavating 
pits  where  the  material  has  to  be  loaded  into  cars  standing  on 
the  surface  of  the  ground. 

Excavator-buckets  are  usually  either  clam-shell  or  orange-peel 
buckets.  The  orange-peel  bucket,  Fig.  53,  patented  and  built 


FIG.  53. 

by  the  Hayward  Company  of  New  York,  consists  of  four  curved 
triangular  blades,  and  when  closed  forms  a  tight  hemispherical 
receptacle,  containing  the  earth  or  other  excavated  material. 
When  open  the  blades  resemble  sharp  spades  which  are  so  ad- 
justed that  the  maximum  digging  effect  is  produced  with  but  a 
slight  tendency  to  lift  the  bucket  when  closing.  Horizontal  arms 
are  riveted  to  the  blades,  and  their  inner  ends  are  attached  to  a 
central  block,  while  the  outer  ones  are  hinged  to  vertical  con- 


130  EARTH  AND  ROCK  EXCAVATION. 

necting-rods,  pivoted  at  their  upper  ends  to  the  upper  center 
block.  The  power  wheel  for  closing  the  bucket  is  fastened  to 
the  lower  central  block,  and  is  somewhat  eccentric  in  shape,  so 
that  it  gives  its  maximum  power  just  as  the  bucket  begins  to 
close.  The  bucket  is  well  braced,  and  the  shaft  is  extended  on 
either  side  to  receive  the  cams,  to  which  are  attached  the  two 
power  chains  suspended  from  pulleys  and  carried  either  by  the 
boom  of  a  derrick  or  by  the  ropeways  of  hoisting  and  conveying  ma- 
chines, and  guided  by  the  two  drums  of  the  engine.  The  capacity 
of  the  bucket  varies  from  ^  to  1  cu.  yd.,  according  to  the  dimen- 
sions. In  buckets  of  1  cu.  yd.  capacity  the  diameter  is  5  ft. 
7  ins.,  and  the  whole  bucket  is  7  ft.  3  ins.  high.  When  open  it  is 
6  ft.  5  ins.  in  diameter  and  8  ft.  4  ins.  high. 

The  other  form  of  buckets  used  with  intermittent  excavating 
machines  is  the  clam-shell,  which  takes  its  name  from  its  similarity 
to  the  shell  of  a  clam,  as  indicated  in  Fig.  54.  The  clam-shell 


FIG.  54. 

bucket  is  composed  of  two  steel  scoops  hinged  together  so  that  by 
means  of  chains  they  may  be  opened  or  closed  at  the  will  of  the 
engineer.  The  bucket  excavates  in  the  same  manner  as  the  orange- 
peel  bucket. 

The  clam-shell  or  grabbing  bucket,  as  it  is  more  properly 
called,  has  the  edges  of  the  scoops  which  come  in  contact  with 
the .  earth  arranged  in  different  ways,  according  to  the  material 
into  which  it  has  to  work.  The  edges  are  made  plain  when  the 


EARTH  EXCAVATION:  INTERMITTENT  DIGGING-MACHINES.    131 

machine  has  to  excavate  very  loose  soil,  as  quicksand,  mud,  etc. 
For  clay  a  grab  with  spaces  between  the  tines  is  most  suitable; 
for  hard,  sandy  material  a  gf&b  with  interlocking  tines,  set  close 
together,  is  necessary;  and  for  gravel  and  rock  an  open-tined 
grab  is  used  as  .shown  by  Figs.  55. 

These  intermittent  machines  can  be  operated  by  one  or  two 
chains.  When  provided  with  only  one  chain  the  grab  must 
necessarily  be  fitted  with  additional  levers  and  catches,  which  are 
very  liable  to  get  out  of  order;  it  is  wrong  in  principle  to  connect 


FIG.  55. 

intricate  working  parts  with  a  bucket  or  grab  which  is  constantly 
in  motion  and  thus  cannot  receive  proper  attention  from  the 
driver  in  lubrication,  etc.  Besides,  with  the  single  chain  the 
bucket  must  be  raised  to  a  certain  height  to  be  discharged,  while 
with  the  double  chain  the  bucket  can  be  opened  and  closed  in 
any  position.  It  is  often  necessary  to  hoist  the  grab  over  some 
projection  and  lower  it  again  before  discharging,  which  can  only 
be  done  by  means  of  two  chains.  For  the  above  reasons  the 
double-chain  system  is  always  preferable. 

Intermittent  digging-machines  provided  with  grabbing-buckets 
are  more  usually  employed  in  dredging  than  in  earth  excavation 
on  land.  Here,  however,  they  are  beginning  to  appear  and,  perhaps, 
will  be  extensively  used  when  better  known  and  appreciated  by 


132 


EARTH  AND    ROCK    EXCAVATION. 


engineers  and  contractors.  In  cases  in  which  the  machine  must 
remain  on  top  of  the  embankment  to  be  removed,  and  the  ex- 
cavated materials  hauled  to  the  dumping  places  on  roads  laid 
at  the  level  of  the  top  of  the  embankment,  these  machines  are  very 
efficient  and  can  be  advantageously  employed.  Another  great 
advantage  is  their  ability  to  excavate  from  20  to  30  ft.,  and  even 
deeper,  by  simply  elongating  the  hoisting-ropes,  an  advantage 
which  is  not  possessed  by  any  other  machine. 

These  down-digging  intermittent  machines  provided  with 
grabbing-buckets  are  generally  mounted  on  a  platform  car  run- 
ning on  tracks.  On  the  rear  end  of  the  platform  is  located 
the  boiler,  which  is  usually  of  the  vertical  type,  and  often  the 
boiler  is  accompanied  by  a  wrought-iron  water-tank.  The  engine 
operating  the  bucket  has  two  cylinders  strongly  fixed  to  cast-iron 
side  frames,  which  work  the  lifting-drum  without  gearing,  and 
are  designed  for  working  the  self-acting  bucket  and  grab  at  a 
great  speed,  together  with  all  necessary  working  parts,  including 
lifting,  lowering,  and  turning  gear,  etc.  The  jib  or  boom  can  be 
made  either  of  wood  or  steel,  and  its  lower  end  stands  in  the  center 
of  a  turntable  or  bull-wheel  attached  so  that  it  can  turn  around  a 
pivot  center.  The  upper  end  of  the  boom  is  commanded  by 
means  of  the  rods  to  the  A  frame  placed  at  the  front  of  the  plat- 
form car.  From  the  top  of  the  boom  is  suspended  the  grabbing- 
bucket,  whose  various  movements  are  regulated  by  the  engineer. 

The  efficiency  of  these  machines  varies  with  the  different 
kinds  of  soil  and  the  capacity  of  the  buckets.  The  Priestman 
Brothers,  Ltd.,  of  London,  in  their  catalogue  give  the  following 
figures  as  the  approximate  quantities  of  material  one  man  will 
raise  (by  steam)  per  day  of  ten  hours  at  an  average  depth  of 
20ft.: 


Capacity 
of  Bucket 
or  Grab, 

Tons  of 
Mud. 

Sand. 

Clay. 

Size  in  Cwts. 

10 

250 

200 

150 

20 

500 

400 

300 

30 

650 

550 

400 

40 

800 

700 

500 

CHAPTER  XL 

METHODS  OF  HAULING  EXCAVATED  MATERIALS  ON  LEVEL 

ROADS. 

UNDER  the  general  name  of  hauling  is  included  the  transpor- 
tation of  excavated  materials  from  the  cuts  and  borrow-pits  to 
the  various  fills  or  spoil-banks.  Such  transportation  can  be  accom- 
plished in  so  many  different  ways  that  it  would  be  almost  impos- 
sible to  give  a  full  description  of  them  all.  For  sake  of  conve- 
nience, however,  and  in  order  to  facilitate  the  review  of  the  most 
important  means  of  transportation  at  the  disposal  of  engineers 
and  contractors,  hauling  will  be  considered  here  under  four  head- 
ings, according  to  the  roads  along  which  the  materials  are  hauled : 

(1)  When  the  earth  is  hauled  on  horizontal  roads  or  roads 
having  only  a  small  gradient. 

(2)  When   the   roads   are   very   steep,   and   consequently  the 
materials  must  be  hauled  along  inclines. 

(3)  When  the  materials  are  hauled  in  a  vertical  direction  or 
hoisted. 

(4)  When  the  materials,  instead  of  being  transported  on  roads 
laid  on  the  ground-surface,  are  hauled  on  roads  suspended  in  the 
air. 

For  each  one  of  these  groups  there  is  a  large  variety  of  means 
of  hauling,  whose  convenience  will  depend  upon  many  circum- 
stances, but  chiefly  upon  the  quantity  of  material  to  be  trans- 
ported and  the  peculiar  conditions  of  the  work.  These  elements 
should  be  accurately  determined  by  the  engineer  and  contractor, 
so  as  to  choose  the  most  efficient  means  of  hauling  in  the  particu- 
lar case  with  which  they  have  to  deal.  It  is  only  by  doing  this 
that  the  work  can  be  performed  with  the  greatest  economy. 

^ 


134  EARTH  AND  ROCK  EXCAVATION. 

Speaking  of  the  hauling  of  excavated  materials  in  a  general 
way,  it  is  necessary  to  remark  that  the  earths  when  removed  from 
their  natural  beds  increase  in  volume  and  consequently  the  quan- 
tity of  earth  hauled  will  be  greater  than  is  found  from  measuring 
the  cut.  This  is  an  important  item  to  be  remembered,  because 
it  is  liable  to  lead  to  great  disappointment,  especially  when,  on 
account  of  competition,  the  bids  for  the  work  are  prepared  with 
only  a  very  narrow  margin.  The  writer  thinks  that  the  swelling 
of  earth  after  being  dug  is  directly  proportional  to  the  cohesion 
of  the  material,  and  consequently  the  more  compact  the  soil  is 
the  greater  is  the  increase  of  volume.  Trautwine  says  that  earth 
when  dug  and  loosely  thrown  out  swells  about  one-fifth  part,  so 
that  a  cubic  yard  in  place  averages  about  1^  or  1.2  cubic  yards 
when  dug;  or  1  cu.  yd.  dug  is  equal  to  f  or  to  0.8333  of  a  cubic 
yard  in  place.  Rock  increases  in  volume  from  25  per  cent,  in 
the  case  of  small  or  medium  fragments  and  road  metalling  to  60  or 
70  per  cent,  in  large  fragments  carelessly  piled. 

In  many  public  works  the  quantity  of  earth  hauled  away  is 
calculated  by  counting  the  carts  and  wagons,  whose  capacity  has 
been  previously  measured.  This  foolish  manner  of  measuring 
earth  originated  the  mistaken  belief  so  common  among  engineers 
and  contractors  in  this  country  that  earth  when  placed  in  em- 
bankments will  shrink  from  the  volume  measured  in  the  pit. 
Counting  the  wagons  for  measuring  the  hauled  earth  is,  however, 
very  convenient  to  the  contractors.  It  requires  the  continuous 
presence  of  a  representative  of  one  of  the  contracting  parties  and 
consequently  a  complication  in  the  calculations  and  greater 
expense.  It  is  used  only  on  city  or  state  works  where  the  con- 
tracting party  does  not  seek  for  economical  work,  but  to  give 
employment  to  as  many  political  friends  as  possible. 

HAULING  ON  HORIZONTAL  OR  NEARLY  HORIZONTAL  ROADS. 

The  easiest  way  of  removing  excavated  materials  is  by  hauling 
them  along  ordinary  roads  which  are  horizontal  or  have  only  a 
small  gradient.  This  is  performed  with  different  devices  or  im- 


HAULING  EXCAVATED  MATERIALS  ON  LEVEL  ROADS.     135 

plements  whose  description  will  form  the  subject  of  the  present 
chapter.  Each  of  the  described  means  of  hauling  is  very  effi- 
cient, but  they  cannot  be  tufed  indiscriminately.  In  each  par- 
ticular case  the  engineer  has  to  deal  with  there  is  always,  accord- 
ing to  the  distance,  one  means  of  hauling  which  is  more  con- 
venient than  any  other.  It  is  for  the  purpose  of  determining 
the  most  convenient  means  of  hauling  in  each  case  that  this 
description  has  been  supplied  with  tables  which  can  be  easily 
changed  according  to  the  data  varying  with  the  localities.  The 
calculation  has  been  based  on  the  prices  in  the  city  of  New  York, 
where  the  wages  are  higher  than  anywhere  else. 

In  hauling  materials  on  ordinary  roads  it  is  necessary  to 
take  into  consideration  the  grade  of  the  road.  Thus,  if  the  road 
is  horizontal  or  descending,  it  is  its  horizontal  projection  that  is 
considered  as  the  real  distance;  but  if  the  road  has  an  ascending 
grade,  the  distance  or  length  of  the  haul  is  given  by  the  formula 

L(l  +  O.Ola), 

where  L  is  the  horizontal  projection  of  the  road,  and  a  a  coefficient 
varying  with  the  grade  and  with  the  means  of  transportation  as 
follows : 

When  the  hauling  is  done  by  means  of  wheelbarrows,  carts, 
or  wagons 

0-1,    2,     3,     4,     5,     6,     7,     8,     9,     10%, 
and 

a  =  5,   11,   18,   25,   33,   43,   54,   67,   82,   100%; 

and  when  by  cars  running  on  tracks 

0-1,  2,    3,     4,     5,     6,     7,     8,    10,    12,     14,     16,     20%; 
and 

a  =  3,  8,  13,  18,  23,  31,  38,  56,  85,   104,   124,   150,   180%. 

In  practical  work  and  for  rough  calculation  it  is  usually  as- 
sumed that  the  hauling  of  the  materials  done  by  means  of  wheel- 
barrows on  roads  having  a  grade  varying  from  1  to  8  per  cent,  is 
nine-tenths  of  what  it  will  be  if  done  on  horizontal  roads,  and 


136  EARTH  AND  ROCK  EXCAVATION. 

with  carts  and  wagons  hauled  by  horses  on  good  roads  of  the 
same  inclination  as  above  eight-tenths.  When  the  hauling  is  done 
on  newly  opened  roads,  without  any  road-bed  or  paving  and 
with  an  inclination  not  greater  than  7  per  cent.,  the  efficiency 
of  the  hauling  is  only  eight-tenths  of  what  it  will  be  if  done  on 
horizontal  roads. 

For  sake  of  simplicity  and  to  facilitate  the  review  of  the  various 
means  of  hauling  materials  on  horizontal  roads,  they  will  be 
divided  in  regard  to  the  motive  power  employed  and  grouped  as 
follows: 


Man  

f  Wheelbarrows. 

Animal 

\  Hand-carts. 

Power. 

{Drag  and  wheel  scrapers. 

Materials 

Horse  

Carts  and  wagons. 

hauled  by  ' 

Cars  on  narrow-gauge  tracks 

Mechanical  I 
Power.      1 

:  Steam  or 
Electricity.  .  . 

f  Cars  on  narrow-gauge  tracks 
\  Cars  on  standard-gauge  tracks. 

Wheelbarrow. — The  oldest  and  the  simplest  means  of  hauling 
small  quantities  of  earth  to  a  short  distance  is  by  wheelbarrows. 
This  implement  consists  of  a  wooden  box  resting  on  a  frame  made 
of  two  inclined  beams  converging  at  the  front  and  having  between 
their  forward  ends  a  small  wheel.  At  the  rear  end  of  the  box 
there  are  two  short  legs,  so  that  the  barrow  when  at  rest  will 
stand  on  these  three  supports.  The  diverging  beams  end  in  the 
shape  of  handles.  There  are  barrows  of  different  patterns  on 
the  market,  and  the  best  is  the  one  in  which  the  distance  apart 
of  the  center  of  gravity  of  the  load  and  the  wheel-axle  is  the  smallest 
possible.  It  would  be  also  convenient  to  have  the  wheel  of  large 
radius,  but  such  a  construction  would  increase  the  weight  of  the 
barrow  and  it  is  thus  advisable  to  make  the  radius  of  the  wheel 
between  15^  and  19  ins.  The  box  is  arranged  in  such  a  way  as 
to  have  the  load  as  near  as  possible  to  the  front  wheel  when  in 
motion.  The  unloading  of  the  material  from  wheelbarrows  is 
easily  done.  When  the  dumping  place  has  been  reached,  the 
laborer  raises  up  the  handles  so  as  to  throw  the  weight  on  the 
front  wheel,  then  with  one  hand  he  pushes  down  one  of  the  handles, 


HAULING  EXCAVATED  MATERIALS  ON  LEVEL  ROADS. 


137 


while  he  raises  up  the  other  handle,  thus  causing  the  barrow  to 
tilt  and  unload  its  contents.  " 

it 


Fig.  56  represents  the  wheelbarrow  used  in  Germany  of  3  cu. 
ft.  capacity.  The  box  is  above  the  handles,  and  the  sides  flare 
out  from  the  bottom.  Fig.  57  represents  the  ordinary  American 
wheelbarrow,  in  which  the  box  is  flat  like  a  tray,  the  diameter 
of  the  wheel  is  17  ins.,  and  the  capacity  varies  from  3  to  5  cu.  ft. 


FIG.  57. 


Wheelbarrows  are  also  constructed  with  the  tray  of  iron,  and 
others  are  made  entirely  of  iron,  but  their  great  cost  is  a  serious 
obstacle  to  their  employment  in  public  works  where  these  vehicles 
are  roughly  handled.  When  they  are  made  of  wood  they  can  be 
easily  repaired  by  any  ordinary  carpenter,  but  when  made  of 


138  EARTH  AND  ROCK  EXCAVATION. 

iron  the  repairing  is  more  expensive,  the  services  of  a  skilled 
mechanic  being  then  required. 

Many  improvements  have  been  lately  made  to  wheelbarrows 
which  are  covered  by  patents;  for  instance,  the  Allen  spring 
barrow,  built  by  C.  W.  Hunt  Company  of  New  York,  illustrated 
in  Fig.  58.  This  barrow  is  provided  with  springs  under  the  bear- 


FIG.  58, 

ings  of  the  wheel,  so  that  it  is  much  easier  to  handle  and  runs 
over  irregularities  without  violent  shocks  to  either  the  workman 
or  the  load.  They  are  built  of  different  sizes,  with  a  capacity 
varying  from  3J  to  8  cu.  ft.  They  are  quite  expensive,  their 
price  being  from  $15.50  to  $20. 

The  cost  of  hauling  a  unit  of  volume  of  earth  by  means  of  wheel- 
barrows depends  upon  the  distance.  Assuming  that  a  man  with 
a  load  can  travel  10  miles  a  day,  he  will  carry  loads  only  half  of 
this  distance,  the  other  half  being  employed  in  returning  with 
the  empty  barrow.  It  is  evident  that  the  shorter  the  distance 
the  greater  will  be  the  number  of  trips  he  can  make,  carrying  each 
time  3  cu.  ft.  of  earth;  and  since  the  cost  of  hauling  is  given  by 
the  wage  of  the  laborer,  the  greater  the  quantity  of  earth  carried 
in  a  day  the  smaller  will  be  the  cost  of  hauling  per  unit  of  volume. 
The  following  table  gives  the  number  of  trips  and  the  quantity 
of  material  carried  by  a  laborer  with  wheelbarrow,  at  various 
distances,  also  the  cost  of  the  work  per  cubic  yard.  These  figures 
have  been  deduced  by  considering  a  day's  work  as  10  hours  and 
the  wage  of  the  laborer,  $1.50  per  day. 

From  this  table  it  is  clearly  seen  that  wheelbarrows  are  very 
convenient  for  small  distances,  but  that  this  manner  of  hauling 
becomes  too  expensive  for  distances  of  300  ft.  or  more. 


HAULING  EXCA-VATED  MATERIALS  ON  LEVEL  ROADS. 


139 


Quantity  of  Earth  Carried. 

Distance, 

Number  of 

t 

Cost  per 

Feet. 

Round  Trips. 

«r 

CJ&c  Feet. 

Cubic  Yards. 

Cubic  Yard. 

50 

528 

1584 

58.44 

$0.025 

100 

264 

792 

29.22 

0.050 

150 

170 

510 

19 

0.079 

200 

132 

396 

14.61 

0.100 

250 

106 

318 

12 

0.125 

300 

88 

264 

10 

0.150 

350 

75 

225 

8 

0.187 

400 

66 

198 

7.3 

0.205 

450 

59 

177 

6.5 

0.230 

500 

53 

159 

5.9 

0.254 

Hand-carts. — It  is  desirable  to  increase  the  capacity  of  the 
vehicle  with  the  increasing  of  the  distance  of  transportation-  of 
the  excavated  materials.  This  is  usually  done  by  means  of 
hand-carts,  which  are  small  carts  having  a  capacity  varying  from 
7  to  10  cu.  ft.  They  are  composed  of  a  wooden  frame  fixed  to  a 
platform  of  the  same  material  and  surrounded  by  boards  forming 
the  box  and  resting  on  a  single  pair  of  wheels  3  or  4  ft.  in  diameter. 
In  continuation  of  the  frame,  at  the  center  of  the  front  of  the  box 
there  is  a  shaft  about  5  ft.  long  ending  with  a  cross-piece.  The 
cart  is  moved  by  two  men  who  place  themselves  behind  this  cross- 
piece  and  push.  To  dump  the  cart  the  men  turn  so  as  to  have  the 
rear  of  the  cart  on  the  edge  of  the  dump,  then  they  remove  the  rear 
board  of  the  box  and  raise  up  the  shaft ;  the  box  turning  over  the 
axle  of  the  wheels  takes  an  inclined  position,  and  the  excavated 
earth  it  contained  falls  to  the  ground.  Hand-carts  are  very 
commonly  employed  in  Germany,  but  very  seldom  if  ever  in  this 
country  or  in  England. 

The  cost  of  hauling  earth  by  means  of  hand-carts  is  given  by 
the  wages  of  the  two  laborers.  It  varies  with  the  distance  the 
excavated  materials  have  to  be  transported.  The  following 
table  indicates  the  cost  of  hauling  earth  at  various  distances  by 
means  of  a  hand-cart  of  8  cu.  ft.  capacity,  hauled  by  two  men  at 
$1.50  per  day  and  traveling  with  load  12  miles  per  day  of  10 
hours : 


140 


EARTH    AND    ROCK    EXCAVATION. 


Quantity  of  Earth  Carried  in  a  Day. 

Distance, 
Feet. 

Number  of 
Round  Trips. 

Cost  per 
Cubic  Yard. 

Cubic  Feet. 

Cubic  Yards. 

200 

158 

1264 

47 

$0.064 

300 

105 

844 

31.3 

0.096 

400 

80 

640 

23.7 

0.12^ 

500 

63 

504 

18.7 

0.160 

600 

53 

422 

15.6 

0.193 

700 

45 

340 

12.6 

0.237 

800 

40 

320 

11.8 

0.254 

900 

35 

2^0 

10.4 

0.2S8 

1000 

31 

252 

9.4 

0.320 

Drag  Scrapers. — Another  means  of  hauling  away  earth  which 
has*  been  already  removed  from  its  natural  position  is  by  drag 
scrapers  (Figs.  59-61).  These  consist  of  a  box  made  up  of  smooth 
sheet  steel  open  on  the  front,  where  it  is  provided  with  a  sharp 
cutting  edge.  Near  the  front  and  pivoted  to  the  two  sides  of  the 


FIG.  59. 


FIG.  60. 


FIG.  61. 


box  there  is  a  steel  bail  in  the  shape  of  an  inverted  U,  furnished 
with  an  eye  in  the  center  to  which  the  horses  are  hitched.  At  the 
rear  end  the  box  is  provided  with  two  wooden  handles  for  the 
filling  and  dumping  the  scraper.  Each  drag  scraper  requires  a 
team  of  two  horses,  with  a  driver  who  operates  the  scraper.  To 
fill  the  box  the  driver  raises  up  the  handles  to  a  small  angle  so  that 
the  cutting  edge  penetrates  the  earth,  and  the  scoop  is  filled  with 
the  dirt  while  the  horses  are  moving.  He  then  drops  the  handles. 


HAULING  EXCAVATED  MATERIALS  ON  LEVEL  ROADS.    141 

and  the  loaded  scoop  is  dragged  along  the  ground.  When  the 
dumping  place  has  been  reached  the  operator  raises  up  the  handles 
until  the  front  edge  engages  fne  soil,  and  the  scoop  rotates  around 
the  pivots  of  the  bail  and  the  load  falls  onto  the  ground. 

The  two  parts  of  the  scraper  subjected  to  great  wear  are  the 
bottom  and  the  sharp  edge.  The  bottom  of  the  scraper  especially, 
being  dragged  on  the  ground,  is  very  soon  worn  out,  and  to  prevent 
this  it  is  reinforced  either  by  runners  placed  longitudinally,  as 
indicated  in  Fig.  59,  or  by  an  extra  flat  steel  bottom,  as  shown  in 
Fig.  60,  which  may  be  removed  and  changed  when  worn.  The 
cutting  edge,  especially  when  working  through  gravel,  hard-pan, 
etc.,  is  also  easily  ruined,  and  it  is  better  to  have  it  made  inter- 
changeable. 

The  capacity  of  drag  scrapers  varies  from  4^  to  5^  cu.  ft. 
They  are  very  efficient  in  the  excavation  of  earth  not  deeper 
than  2J  or  3  ft.  and  where  the  materials  have  to  be  hauled  to  a 
distance  not  greater  than  200  ft. 

Drag  scrapers  can  be  considered  as  self-loading  and  dumping 
vehicles,  and  they  are  used  in  hauling  away  materials  which  have 
been  broken  up  by  means  of  a  plow.  It  is  in  connection  with 
plows  and  for  short  hauls  that  these  means  of  transportation  are 
most  efficient. 

The  cost  of  hauling  by  means  of  drag  scrapers  is  easily  calcu- 
lated; it  depends  upon  the  distance  of  the  haul.  The  only  expenses 
are  the  hiring  of  the  team  and  the  wage  of  the  driver,  the  interest 
of  the  capital  invested  in  the  scraper,  as  well  as  its  sinking  fund,  being 
too  small  to  be  taken  into  consideration.  The  cost  of  hiring  the 
team  is  about  $5,  while  the  driver  gets  $1.50  a  day,  so  that  the  total 
expenses  will  amount  to  $6.50  per  day.  Since  the  driver  must 
walk  continuously,  it  is  considered  that  the  horses  will  drive  15 
miles.  The  capacity  of  the  scraper  being  on  the  average  5  cu.  ft., 
the  number  of  trips,  including  also  the  return  for  loading,  and  the 
cost  per  unit  volume  are  given  in  the  following  table: 


142 


EARTH    AND    ROCK    EXCAVATION. 


Distance, 

Number  of 

Cubic  Yards 

Cost  of  Haul- 

Feet. 

Trips. 

Hauled  per 

ing  One 

Day. 

Cubic  Yard. 

100 

400 

74 

$0.09 

150 

300 

55.5 

0.116 

200 

200 

37 

0.18 

300 

150 

27.5 

0.23 

400 

100 

18.5 

0.34 

500 

80 

15 

0.43 

600 

66 

11 

0.60 

Wheeled  Scrapers. — Wheeled  scrapers  are  more  convenient 
than  drag  scrapers  for  conveying  materials.  These  consist  of  a 
box  or  pan  made  of  one  piece  of  sheet  steel  bent  without  heating. 
Their  dimensions  are  3X3  ft.XlS  ins.  deep,  and  when  full  contain 
from  J  to  J  cu.  yd.  The  box,  as  in  the  drag  scraper,  is  open  in  front 
and  can  be  raised  and  lowered,  and  also  revolved  around  a  horizontal 
axis  by  means  of  a  lever.  The  wheels  are  36  ins.  in  diameter  and 
are  provided  with  broad  tires  to  prevent  them  from  sinking  into 
the  loose  earth. 

To  fill  the  box  while  the  horses  are  moving  and  dragging  the 
machine  forward  the  driver  pulls  up  the  lever,  and  the  pan  hits 
the  ground  at  a  small  angle  which  is  regulated  automatically. 
The  edge  of  the  pan  scrapes  the  soil,  and  the  box  is  filled  with 
earth;  then  the  driver  pulls  down  the  lever,  and  the  pan  is  raised 
about  1  ft.  from  the  ground,  and  in  this  position  it  travels.  When 
the  dumping  place  has  been  reached  the  driver  pulls  up  the  lever, 
the  front  edge  of  the  pan  engages  the  earth,  and  the  box  turns 
around  its  axis,  thus  unloading  its  contents.  Wheeled  scrapers, 
consequently,  can  be  considered  as  self-loading  and  dumping  cars. 

Wheeled  scrapers  of  different  forms  are  found  on  the  market. 
Notwithstanding  they  are  built  by  different  manufacturers  and 
are  all  covered  by  patents,  they  are  all  similar  in  the  essential 
parts  and  vary  only  in  details,  as,  for  instance,  levers,  attach- 
ments, latches,  special  arrangements  for  unloading,  etc.  Fig.  62 
represents  one  of  the  wheeled  scrapers  built  by  the  Western  Wheeled 
Scraper  Company,  of  Aurora,  111. 

Wheeled  scrapers  are  made  of  different  sizes,  their  capacity 


HAULING    EXCAVATED    MATERIALS    ON    LEVEL    ROADS. 


143 


varying  from  9  to  14  cu.  ft.  ,  The  smaller  machines  require  a  team 
of  two  horses,  with  a  driver  who  handles  the  lever  and  regulates 
the  work  of  the  seraper;  The  larger  ones  require  another  man 
besides  the  driver.  The  smaller  sizes  will  remove  the  earth 
cheaper,  on  a  short  haul,  than  the  drag  scraper,  while  the  larger 
sizes  are  convenient  for  long  hauls.  These  means  of  transporta- 
tion are  very  convenient  in  excavations  which  are  not  deeper 
than  3  or  4  ft.,  as,  for  instance,  in  preparing  the  work  for  more 


FIG.  62. 

powerful  machines  or  removing  the  earth  above  rock  which  has 
to  be  blasted.  In  the  excavation  of  the  Chicago  Drainage  Canal 
wheeled  scrapers  were  extensively  used,  and  they  hauled  up  to 
46  cu.  yds.  per  day. 

The  efficiency  of  the  work,  however,  depends  upon  the  size  of 
the  scoop  and  the  distance  to  which  the  material  is  to  be  hauled. 
In  the  following  table  are  given  the  quantity  of  the  material 
hauled  by  wheeled  scrapers  of  9  and  14  cu.  ft.  capacity,  and  the 
cost  for  the  various  distances.  The  prices  are  calculated  on  the 
basis  of  those  paid  in  New  York,  and  when  the  work  is  done  in 
the  country  the  prices  given  should  be  reduced  at  least  one-third. 

From  this  table  it  is  seen  that  the  cost  of  hauling  material  by 
means  of  wheeled  scrapers  increases  with  the  distance,  and  even  when 


144 


EARTH  AND  ROCK   EXCAVATION. 


reduced  one- third  the  prices  given  remain  high.  To  remedy  this 
the  Western  Wheeled  Scraper  Company  put  on  the  market  a  ma- 
chine which  was  a  combination  of  scraper  and  wagon.  This  machine 


Distance, 

Number  of 

Scoop  9  Cubic 
Feet;  Amount 
of  Material 

Scoop  14  Cubic 
Feet;  Amount 
of  Material 

Cost  per  Cubic  Yard. 

Feet. 

Trips. 

Hauled  in  a 

Hauled  in  a 

Day  in  Cubic 
Yards. 

Day  in  Cubic 
Yards. 

Nine  Cubic  - 
foot  Scoop. 

Fourteen  Cubic- 
foot  Scoop. 

200 

200 

70 

103 

$0.093 

$0.077 

300 

133 

44 

70 

0.147 

0.114 

400 

100 

33 

51.5 

0.200 

0.115 

500 

80 

27 

41.3 

0.240 

0.193 

600 

66 

22 

34.2 

0.290 

0.234 

700 

57 

19 

29 

0.370 

0.276 

800 

50 

16.5 

25.7 

0.400 

0.311 

900 

44 

14.7 

21.7 

0.44 

0.366 

1000 

40 

13 

20 

0.50 

0.400 

consisted  of  two  wheeled  scrapers  of  large  capacity  carried  on  a 
frame  supported  by  four  wheels.  The  two  ecrapers  were  operated 
independently  from  one  another;  the  front  pan  was  loaded  first 
and  was  raised  to  its  place,  the  second  pan  was  then  lowered  and 
loaded  and  raised.  Since  the  two  pans  had  together  a  capacity  of 
1 J  cu.  yds.,  they  required  from  two  to  three  horses  to  pull  them. 


FIG.  63.  FIG.  64 

But  these  machines  have  not  met  with  success  since  their  con- 
struction has  been  discontinued. 

Another  but  simpler  machine  which  found  great  favor  with 
contractors,  especially  in  handling  the  earth  that  might  be  dumped 
to  a  distant  point,  is  the  one  illustrated  in  Figs.  63  and  64.  This 
consists  of  an  ordinary  wheeled  scraper  of  large  capacity,  the  only 
difference  being  that  it  is  provided  with  a  front  scoop  closing  the 


HAULING  EXCAVATED  MATERIALS  ON  LEVEL  ROADS.    145 

pan  of  the  scraper  and  firmly  retaining  its  contents.  In  this 
mariner  the  earth  loaded  in|p  the  scraper  will  be  carried  to  the 
dumping  place  without  spreading  it  all  over  the  road,  as  usually 
happens  with  the  ordinary  scrapers.  The  front  scoop  is  fixed  and 
engages  the  scraper  when  it  is  raised  and  loaded.  Fig.  63  shows  the 
machine  closed,  while  Fig.  64  shows  the  machine  when  the  scraper 
is  lowered  and  ready  to  be  loaded.  Such  a  wheeled  scraper  can 
be  considered  as  a  self-loading  and  dumping  cart,  and  it  is  certainly 
very  convenient,  since  it  eliminates  two  expensive  items  entering 
into  the  cost  of  the  earthworks,  viz.,  the  loading  and  unloading  of 
the  earth  into  the  carts. 

Carts  and  Wagons. — The  transportation  of  excavated  mate- 
rials to  a  great  distance  is  usually  done  by  larger  vehicles  hauled 
by  horses.  These  vehicles  vary  greatly,  but  are  either  carts  or 
wagons,  a  distinction  which  is  made  according  to  the  number  of 
wheels.  They  are  called  carts  when  provided  with  only  two 
wheels  of  large  dimensions,  while  those  provided  with  four  wheels 
—two  small  ones  in  front  and  two  larger  ones  behind — are  called 
wagons.  Both  carts  and  wagons  can  be  divided  again  into  ordi- 
nary and  self-dumping,  according  to  whether  the  material  is 
unloaded  by  hand  or  dumped  automatically. 

Carts. — Ordinary  carts,  called  also  equilibrium  carts,  are  very 
similar  to  the  hand-carts  described  above,  with  the  difference  that 
they  are  of  larger  dimensions.  They  consist  of  two  large  wheels, 
from  5  to  6  ft.  in  diameter,  and  a  box  firmly  fixed  to  the  axle  of 
the  wheels  and  provided  with  two  shafts  to  which  the  horse  is 
hitched.  The  capacity  of  the  cart  varies  from  20  cu.  ft.  to  1  cu. 
yd.  It  affords  a  very  convenient  means  of  transportation  on 
roads  having  even  an  inclination  of  8  per  cent.  To  unload  the 
cart,  usually  the  driver  detaches  the  horse  and  pulls  up  the  shafts, 
and  the  cart  revolving  around  its  axle  causes  the  material  to  fall 
off. 

Dump-carts.  —  Very  similar  to  ordinary  carts  are  those 
which  dump  the  materials  without  being  compelled  to  unhitch 
the  horse.  These  carts  are  commonly  known  as  dump-carts,  and 
are  constructed  of  different  materials  and  shapes.  The  one  illus- 


146  /  EARTH  AND  ROCK  EXCAVATION. 

trated  in  Fig.  65  has  the  shafts  fixed  to  the  axle  of  the  wheels,  and 
the  box  is  provided  with  two  supports  at  its  bottom  and  upon 
which  it  rests,  and  may  revolve  around  the  axle.  The  body  of 
the  cart  is  kept  in  a  horizontal  position  by  means  of  two  spurs 
projecting  at  the  front;  the  shafts  are  provided  with  two  eyes 


FIG.  65. 

through  which  passes  an  iron  or  wooden  bar,  for  keeping  the 
spurs  of  the  box  flush  with  the  shafts.  To  unload  the  cart  this 
bar  is  removed,  and  since  the  center  of  gravity  is  just  a  little  at 
the  rear  of  the  axle,  a  simple  push  by  the  driver  will  rotate  the 
box  around  the  axle,  and  the  material  will  fall  from  the  rear  end, 
the  end-board  having  been  previously  removed.  Dump-carts 
are  also  made  of  iron,  as,  for  instance,  the  Hill  dump-cart,  repre- 
sented in  Fig.  66,  which  is  extensively  used  in  the  city  of  New 


FIG.  66. 


York.  The  high  prices  charged  for  these  new  and  patented  dump- 
carts  prevent  their  extensive  use  in  the  hauling  of  the  earth 
excavated  for  engineering  purposes. 


HAULING    EXCAVATED    MATERIALS    ON    LEVEL    ROADS.         147 

Ordinary  Wagons. — The  .  strength  of  animals  is  more  con- 
veniently utilized  when  they  .are  working  in  teams,  as  will  be  seen 
later  on,  and  in  such  cases'' the  materials  are  carried  away  by 
means  of  wagons.  These  consist  of  a  four-wheeled  truck  made 
up  of  heavy  beams  with  a  platform  surrounded  by  boards  so  as 
to  form  a  box  in  which  the  materials  are  deposited.  The  front 
wheels  are  of  smaller  diameter  and  their  axle  is  pivoted  to  the 
frame  of  the  truck  so  that  these  wheels  may  go  under  the  plat- 
form and  the  wagon  turn  in  a  small  circle.  Attached  to  the 
axle  of  the  front  wheels  there  is  a  shaft  to  which  the  horses  are 
hitched.  This  ordinary  wagon  does  not  afford  the  most  con- 
venient way  of  carting  excavated  materials,  because  the  earth 
must  be  unloaded  by  hand,  and  this  expensive  item  will  tend  to 
greatly  increase  the  cost  of  hauling  on  account  of  the  labor  and 
time  required. 

Dumping-wagons. — Dumping-wagons  are  more  convenient, 
and  consequently  more  commonly  employed  in  the  transporta- 
tion of  materials  in  public  works.  These  are  similar  to  ordinary 
wagons,  with  the  difference  that  they  are  provided  with  some 
arrangement  which  will  allow  the  dumping  of  its  contents.  There 
are  numerous  dumping  wagons  on  the  market,  many  of  them 
still  covered  by  patents,  but  those  employed  in  the  hauling  of 
earth  can  be  grouped  as  wagons  in  which  the  bottom  is  removed 
and  the  materials  fall  between  the  wheels,  or  in  which  the  plat- 
form of  the  vehicle  slides  on  the  truck  and  the  material  is  dumped 
from  the  rear  end  of  the  wagon. 

The  simplest  form  of  dumping-wagons  of  the  first  group,  in 
which  the  bottom  of  the  platform  is  removed  and  the  material 
falls  between  the  wheels,  consists  of  an  ordinary  wagon  in  which 
the  platform  is  composed  of  several  square-edged  beams  with 
round  projecting  ends.  They  are  generally  4X4  ins.,  and  are 
placed  close  together  and  resting  on  the  frame  of  the  wagon. 
When  the  driver  wants  to  unload  the  wagon  he  pulls  out  one  of 
these  beams.  All  the  others  then  become  loose  and  the  whole 
platform  may  be  easily  removed,  and  the  material  will  of  course 
fall  on  the  ground  and  between  the  wheels.  This  form  of  wagon, 


148 


EARTH    AND    ROCK    EXCAVATION. 


although  commonly  used  in  the  Highway  Department  of  the  city 
of  New  York,  is  not  advisable  on  public  works  on  account  of  the 
great  length  of  time  required  in  unloading,  and  this  is  perhaps 
the  reason  why  it  was  deemed  desirable  by  the  New  York  politicians. 
More  convenient  than  the  wagon  just  described,  but  of  the 
same  type  is  the  Watson  dump-wagon  illustrated  in  Fig.  67. 
The  wagon  is  so  constructed  that  the  front  wheels  may  pass  under- 
neath the  body  of  the  truck,  thus  allowing  the  wagon  to  turn  in 
a  small  circle.  The  platform  is  made  up  of  two  parts  joined  at 
the  middle,  but  hinged  to  the  sides  of  the  wagon  in  such  a  manner 


FIG.  67. 

that  they  may  be  opened  and  closed  as  the  leaves  of  a  door.  The 
opening  and  closing  of  the  bottom  is  accomplished  by  means  of 
chains  passing  over  gears  at  the  sides  of  the  frame  and  regulated 
by  a  sprocket-wheel  moved  by  a  lever  located  near  the  driver's 
seat.  By  pulling  the  lever  the  chains  loosen  and  the  two  parts 
forming  the  bottom  of  the  wagon  are  opened  and  the  contained 
material  falls  between  the  wheels.  When  the  wagon  is  emptied, 
the  driver  by  reversing  the  lever  causes  the  closing  of  the  bottom, 
and  the  wagon  is  in  position  to  be  again  loaded  with  earth.  The 
opening  and  closing  of  the  wagon,  and  consequently  the  dumping 
operation,  can  be  made  without  any  inconvenience  and  while 
the  horses  are  moving,  so  that  not  a  single  instant  is  lost  for  the 


HAULING    EXCAVATED    MATERIALS    ON   LEVEL   ROADS.         149 

unloading  of  the  wagon.  It  is  no  wonder  that  this  kind  of  wagon 
has  met  with  the  greatest  siiccess,  and  that  they  are  extensively 
employed  in  public  works  for^he  transportation  of  materials. 

Dumping-wagons  of  this  type  are  found  in  great  numbers  on 
the  market;  they  are  all  built  on  the  same  principle,  but  vary  in 
details.  The  differences  chiefly  consist  in  the  arrangement  of  the 
chains  for  the  opening  and  closing  of  the  bottom  of  the  wagon, 
in  the  construction  and  arrangement  of  the  sprocket-wheels  and 
guiding- sheaves,  in  the  lever,  etc.  These  details,  however,  are 
too  insignificant  to  be  considered  in  a  book  like  this,  where  only 
the  various  types  of  machines  and  implements  used  by  engineers  and 
contractors  are  briefly  described. 

A  different  type  of  dumping- wagon  is  the  one  in  which  the 
box  rests  on  a  truck  which  is  provided  with  a  platform.  This 
is  a  little  inclined  toward  the  rear  and  is  furnished  with  iron  bands 
so  as  to  offer  a  smooth  surface  to  the  box  in  sliding.  To  further 
facilitate  the  sliding  the  lower  part  of  the  box  is  provided  with 
iron  rollers.  During  the  transportation,  while  the  wagon  is 
loaded,  the  box  is  fixed  to  the  front  of  the  truck  by  means  of 
heavy  iron  hooks.  To  unload  the  wagon  the  driver  releases  the 
box  from  the  truck  by  disengaging  the  hooks,  and  the  box  slides 
along  the  iron  guides  and  turns  around  the  hind  edge  of  the  truck 
and  assumes  the  position  indicated  in  Fig.  68. 


FIG. 


The  dumping  of  the  material  from  these  wagons,  while  it  does 
not  require  any  work,  will  take  up  some  time,  since  it  is  necessary 
to  stop  the  horses,  the  driver  has  to  loosen  the  box,  and  when 


150 


EARTH    AND    ROCK    EXCAVATION. 


empty  it  must  be  raised  up  and  fastened  again  to  the  truck.  There 
is  no  doubt  that  a  great  deal  of  time  will  be  necessary  for  these 
various  operations,  and  for  this  reason  these  wagons  are  not  so 
convenient  for  the  transportation  of  excavated  earth  as  the  con- 
tractor's dump-wagons  are;  but  they  are  more  commonly  em- 
ployed in  the  transportation  of  building  materials,  as  bricks,  sand, 
building  stones,  etc. 

There  is  still  another  type  of  dumping-wagons,  in  which  the 
box  is  fixed  to  the  truck  during  the  hauling,  but  is  so  arranged 
that  it  may  rotate  around  an  axis.  A  new  dumping- wagon  re- 


FIG.  69. 

cently  patented  and  built  by  the  Shadbolt  Manufacturing  Company 
of  Brooklyn,  and  extensively  used  in  the  construction  of  the  New 
York  Rapid  Transit  Subway,  is  designed  on  this  principle.  The  body 
of  the  wagon  (Fig.  69)  is  balanced  on  the  rear  springs  so  that  it  is 
easily  tilted  without  the  use  of  any  special  mechanism,  the  springs 
resting  on  a  bar  across  the  frame.  The  sockets  in  which  this  bar 
turns  are  set  in  the  frame  sides  at  a  point  in  front  of  the  rear  axle 
just  sufficient  to  throw  part  of  the  load  on  the  front  axle,  thereby 
bringing  the  center  of  gravity  about  1  ft.  back  of  a  certain  point 
between  the  axles,  which  practice  has  shown  to  be  the  best  dis- 
tribution of  load  to  secure  the  easiest  draught  with  wheels  of  the 
relative  height  of  those  in  common  use.  A  chain  is  attached 
to  the  front  end  of  the  car,  and  passes  under  the  front  axle,  re- 
lieving the  strain  caused  by  the  act  of  dumping,  the  front  springs 
serving  as  cushions.  The  chain  can  be  shortened  or  lengthened 


HAULING  EXCA-VATED  MATERIALS  ON  LEVEL  ROADS.    151 

at  will,  thereby  determining  the  angle  at  which  the  wagon  must 
be  tilted,  according  to  the  *  different  conditions  that  govern  the 
operation,  such  as  the  nature  of  the  load,  the  site  where  it  is  to 
be  dumped,  etc. 

The  capacity  of  carts  is  about  1  cu.  yd.,  while  that  of  wagons 
varies  between  1J  and  2  cu.  yds.  For  the  reason  explained  at 
p.  281,  in  hauling  earth,  wagons  should  always  be  preferred  to 
carts,  and  the  type  of  vehicle  selected  should  be  such  as  will  do 
the  work  at  the  smallest  cost. 

In  calculating  the  cost  of  hauling  by  carts  and  wagons  the  fol- 
lowing items  should  be  considered:  (1)  The  daily  wages  for  team 
and  driver,  including  also  the  hiring  of  the  cart;  (2)  the  time 
required  for  loading;  (3)  the  distance  of  hauling;  (4)  the  time 
required  for  unloading  the  car  and  (5)  the  time  employed  on  the 
return  trip.  Comparing  these  various  items  with  the  number  of 
miles  that  a  team  may  travel  in  a  day  and  with  the  number  of 
round  trips  that  can  be  made  in  a  day,  the  cost  of  hauling  a  unit 
of  volume  of  material  to  a  given  distance  will  be  easily  found. 
As  a  rule  it  is  assumed  that  the  transportation  of  the  excavated 
materials  by  means  of  carts  and  wagons  is  not  convenient  for 
distances  greater  than  a  mile. 

Assuming  the  cost  of  hiring  a  horse  and  cart,  the  wages  of  the 
driver  being  included,  to  be  $3.50  per  day,  and  that  of  hiring  a 
team  of  horses  with  wagon  and  driver  to  be  $5,  and  the  capacit  y  of 
the  cart  be  1  cu.  yd.  and  that  of  the  wagon  2  cu.  yds.,  and  that  a 
single  horse  with  a  cart  may  travel  15  miles  per  day  while  the  team 
of  horses  hitched  to  the  wagon  will  travel  20  miles;  the  cost  of 
hauling  the  unit  of  volume  of  earth  at  the  various  distances  will  be  as 
given  in  the  following  table. 

The  hauling  of  the  stones,  obtained  from  the  excavations 
through  rock,  is  usually  done  by  means  of  ordinary  carts  and 
wagons  just  described.  To  easily  load  the  stones  into  these  vehicles 
it  is  necessary  to  break  them  into  small  fragments,  and  this  becomes 
an  expensive  item  when  the  rock  is  removed  from  its  natural  bed 
by  means  of  blasting,  in  which  large  stones  are  detached  from 
the  bank.  To  haul  away  these  large  stones  by  means  of  ordinary 


152 


EARTH    AND    ROCK    EXCAVATION. 


One  Horse  and  Cart. 

Two  Horses  and  Wagon. 

Distjincss 

in  Feet. 

Number  of 
Round  Trips. 

Quantity  of 
Hauled  per 

Cost  per 
Cubic  Yard. 

Number  of 
Round  Trips. 

Quantity  of 
Earth 
Hauled  per 

Cost  per 
Cubic  Yard. 

Cubic  Yard. 

Cubic  Yard. 

500 

79 

79 

$0.044 

105 

210 

$0.024 

1,000 

40 

40 

0.087 

53 

106 

0.047 

1,500 

26 

26 

0.134 

35 

70 

0.072 

2,000 

20 

20 

0.174 

26 

52 

0.094 

2,500 

16 

16 

0.22 

21 

42 

0.12 

3,000 

13 

13 

0.268 

17 

34 

0.15 

4,000 

10 

10 

0.348 

13 

26 

0.188 

5,000 

8 

8 

0.445 

10 

20 

0.25 

6,000 

7 

7 

0.500 

8 

16 

0.31 

7,000 

6 

6 

0.583 

7 

14 

0.36 

8,000 

5 

5 

0.696 

6 

12 

0.41 

9,000 

4 

4 

0.890 

5 

10 

0.50 

10.000 

3 

3 

1.166 

4 

8 

0.62 

carts  and  wagons  presents  a  serious  difficulty,  not  so  much  in 
regard  to  loading  the  stones  into  the  carts  as  in  dumping  them. 
Here,  if  the  vehicle  is  self-dumping,  the  sudden  strain  produced 
by  the  fall  of  such  a  heavy  stone  will  seriously  affect  the  delicate 
parts  of  the  carts — otherwise  it  will  require  a  long  time  and  the 
employment  of  several  men  to  effect  the  unloading  of  the  larger 
stones  of  1,  2,  and  2J  tons  each.  To  avoid  this  inconvenience 
special  cars  are  constructed. 

In  small  excavations,  especially  in  country  works,  one  of  the 
most  convenient  vehicles  for  hauling  large  stones  is  the  stone-boat. 
This  consists  of  three  heavy  boards  made  of  hard,  smooth-grained 
wood,  held  together  by  means  of  two  crosspieces  at  the  ends, 
strongly  nailed  or  bolted,  and  provided  with  an  iron  hook  in  front, 
to  which  the  beam  is  hitched,  as  indicated  in  Fig.  70.  On  this 
very  heavy  stones  can  be  easily  loaded  with  crowbars  or  hand- 
levers. 

The  stone-boat  slides  easily  even  in  the  softest  ground  and 
in  some  cases  it  may  be  found  convenient  even  for  hauling  earth, 
especially  when  the  ground  is  too  soft  for  wagons  or  wheels  of 
any  kind.  When  the  stone-boat  is  used  for  carrying  the  earth, 
one  or  two  strips  of  board  may  be  nailed  on  the  edges.  This  cart  is 
easily  loaded,  since  the  shovelers  do  not  have  to  raise  the  material, 


HAULING  EXCAVATED  MATERIALS  ON  LEVEL  ROADS.    153 

as  in  ordinary  carts  and  wagons,  and  in  many  cases  earth  can  be 
hauled  cheaper  in  this  way  than  in  any  other.     The  stone-boat 


FIG.  70. 

illustrated  in  the  figure  is  the  one  built  by  G.  C.  Pollard  of  Brook- 
lyn, N.  Y. 

The  stone-boat  cannot  be  employed  in  case  the  stones  have  to  be 
hauled  on  paved  roads,  especially  along  the  city  streets,  and  then 
a  specially  constructed  wagon  is  usually  employed.  This  consists 
of  a  four-wheel  truck  in  which  the  front  and  rear  wheels  are  sepa- 
rated. The  platform  of  the  car  is  made  up  of  heavy  planks  rein- 
forced with  iron  bands;  and  it  is  very  low,  being,  as  a  rule,  not 
more  than  1  ft.  from  the  ground.  The  axle  of  the  rear  wheels  is 
above  the  plane  of  the  platform,  and  to  protect  it  from  twisting  under 
the  weight  of  a  large  stone  concentrated  only  at  one  point,  there  is  a 
wooden  incline  arranged. in  the  manner  clearly  indicated  in  Fig.  71. 


I'IG.    71. 


The  center  plank  of  the  platform  is  longer,  and  its  extreme  is  pro- 
vided with  a  hook  which  engages  a  chain  firmly  fixed  in  some  way 
to  the  axle  of  the  front  wheels  of  the  truck.  Such  an  arrangement 


154  EARTH  AND  ROCK  EXCAVATION. 

permits  the  car  to  turn  even  on  sharp  curves.  The  advantage  of 
these  cars  is  that  they  can  be  easily  loaded  and  unloaded.  The 
platform  is  so  low  that  even  large  stones  can  be  easily  placed 
there  by  means  of  levers  and  without  the  necessity  of  having  cranes 
or  derricks.  The  operation  of  unloading  the  car  is  very  simple; 
a  crowbar  is  applied  as  a  lever  under  the  sides  of  the  platform 
of  the  car,  so  that  it  is  raised  up  just  a  little,  but  enough  to  disengage 
the  chain  from  the  hook;  the  front  wheels  are  thus  separated  from 
the  car,  and  the  platform,  deprived  of  one  support,  will  form  now 
an  inclined  plane,  along  which  the  large  stones  may  easily  descend. 
Fig.  71  illustrates  one  of  these  cars  as  commonly  employed  in 
the  city  of  New  York. 


CHAPTER  XII. 

HAULING  EXCAVATED  MATERIALS  ON  HORIZONTAL  ROADS. 

THE  roads  used  to  haul  the  excavated  materials  for  earthworks 
are  generally  without  paving,  and  consequently  their  surface, 
being  of  very  loose  material,  offers  great  resistance  to  traction. 
Hence  in  works  of  some  magnitude  and  when  the  grade  is  not 
greater  than  3  per  cent.,  the  hauling  is  more  conveniently  done 
by  cars  running  on  temporary  tracks,  or  by  means  of  so-called 
industrial  railways.  Industrial  railways  were  invented  by  Decau- 
ville  of  Petit  Bourg,  France,  and  are  now  built  by  different  firms 
all  over  the  world,  as,  for  instance,  by  Legrand  of  Mons,  Belgium; 
Arthur  Koppel  of  Berlin;  Kerr,  Stuart  &  Co.,  Ltd.,  England,  and 
in  America  by  C.  W.  Hunt  Company  of  New  York;  Steubner  of 
Long  Island  City,  N.  Y.;  Ryan  &  McDonald  of  Baltimore,  and 
many  others. 

To  begin  with  the  tracks:  they  generally  vary  in  form  and 
dimensions,  depending  upon  the  load  that  they  have  to  carry. 
Those  built  in  this  country  are  of  the  usual  American  standard 
rail  section  of  small  dimensions,  varying  usually  from  12  to  20  Ibs. 
per  lineal  yard.  The  smaller  sizes  are  employed  to  support  light 
loads  not  more  than  6000  Ibs.,  whilst  the  larger  can  support  cars 
loaded  with  15,000  Ibs.  The  two  rails  are  riveted  to  steel  cross- 
ties,  and  the  truck  is  made  in  sec- 
tions varying  from  16  to  20  ft.  in 
length.  One  end  of  each  section  is 
provided  with  fish-plates,  one  end 
of  which  is  riveted  to  the  rails, 
whilst  the  other  projects  and  is  FlG-  72- 

bolted  to  the  succeeding  section  of  track.      Fig.  72   shows   the 

155 


156 


EARTH    AND    ROCK    EXCAVATION. 


end  of  one  rail  with  the  attached  fish-plates,  ready  to  receive 
the  succeeding  section;  and  Fig.  73  illustrates  one  section  of 
track  as  manufactured  by  Arthur  Koppel  of  Berlin.  Similar 
sections  are  made  in  curves  of  12-ft.  radius  or  more,  and  are  con- 


FIG.  73. 

nected  to  the  straight  line  by  means  of  fish-plates,  as  described 
above. 

The  gauge  of  industrial  railways  generally  varies  from  20 
to  24  ins.,  and  these  gauges  have  been  found  convenient.  The 
gauge  has  not  a  great  influence  upon  the  load  to  be  carried  on 
the  rails,  since  heavy  weights  can  be  easily  hauled  on  narrow- 
gauge  tracks  provided  the  rails  are  strong  enough  to  stand  the 
pressure.  The  total  weight  of  a  straight  section,  with  12-lb. 
rails  and  20-in.  gauge,  complete  with  its  cross-ties,  is  about  28  Ibs. 
per  lineal  yard,  while  the  weight  of  the  same  section,  with  rails 
of  24-in.  gauge,  is  28J  Ibs.  per  yard.  One  section  being  from 
16  to  20  ft.  long,  its  weight  will  vary  between  112  Ibs.  for  a  section 
16  ft.  long,  20-in.  gauge,  and  12-lb.  rail,  and  380  Ibs.  for  a  20-ft. 
section  with  24-in.  gauge  and  20-lb.  rails.  These  are  loads  which 
may  be  easily  taken  up  and  transferred  by  two  men. 

The  cross-ties  of  industrial  railways  are  of  steel,  and  are  usu- 
ally made  of  a  convex  form,  so  that  the  earth  will  be  compressed 
underneath,  thus  forming  a  kind  of  incompressible  cushion  which 
will  prevent  the  sinking  of  the  track  under  the  load.  In  Fig.  74 
is  shown  the  cross-section  of  a  cross-tie  built  by  Arthur  Kappel 
of  Berlin.  The  cross-ties  are  generally  constructed  with  a  large 
bearing  surface  on  the  foundation,  to  support  the  load;  this  area 
in  proportion  to  the  load  is  nearly  double  that  of  the  ordinary 
railroad  cross-tie.  They  are  placed  about  3  ft.  apart,  center  to 
center,  and  there  is  one  cross-tie  near  the  end  of  each  section,  so 


HAULING  EXCAVATED  MATERIALS  ON  HORIZONTAL  ROADS.  157 

that  when  the  line  is  placed  on  the  ground  and  ready  for  service 
the  cross-ties  are  not  equally  spaced,  but  are  closer  near  the  joints 


FIG.  74. 


of  the  rails.  Cross-ties  are  usually  provided  with  two  or  three 
holes,  so  that  they  may  be  nailed  to  planks  laid  underneath  in 
order  to  increase  their  bearing,  thus  making  still  more  difficult 


FIG.  75. 


the  sinking  of  the  tracks  under  the  load,  and  this  is  generally 
done  when  the  ground  is  very  loose  and  wet.  The  rails  are  firmly 
riveted  to  the  cross-ties,  but  in  some  cases,  for  convenience  of 


158  EARTH  AND  ROCK  EXCAVATION. 

shipping  and  to  avoid  high  duties  in  importing  these  industrial 
railways  into  other  countries,  the  cross-ties  are  detached  and 
provided  with  clips  which  will  firmly  hold  in  place  the  lower 
flange  of  the  rail. 

Industrial  railways  like  ordinary  railroads  are  provided  with 
switches.  These  are  usually  arranged  with  a  special  rail  on  a 
•curve  of  12-ft.  radius  and  riveted  up  solid  to  the  cross-ties,  having 
the  switch-points  and  frog  complete.  Switches  are  made  to 
match  the  portable  tracks,  and  are  supplied  either  with  a  right 
or  a  left  curve  as  in  Fig.  75.  There  are  also  three-way  switches, 
as  indicated  in  the  same  figure.  The  switch-point  consists  of  a 
tongue,  which  may  be  moved  around  a  pivot.  The  points  are 
usually  moved  by  the  workmen,  but  with  heavier  rails,  and  when 
the  railway  is  to  be  used  for  a  long  time,  a  switch-stand  mounted 
on  steel  sleepers  is  employed,  and  these  are  built  to  match  any 
line. 

In  connection  with  industrial  railways  there  are  also  turn- 
tables in  order  to  allow  the  cars  to  change,  direction  at  right  angles 
to  the  line.  These  consist  of  two  circular  steel  plates,  the  lower 
one  having  a  grooved  ring  in  which  are  placed  balls  made  of  hard- 
ened steel  acting  as  rollers,  and  kept  in  place  by  a  small  groove 
underneath  the  upper  plate.  A  center  pivot  keeps  the  two  plates 
concentric,  and  while  the  lower  plate  is  fixed  to  the  ground  the 
upper  one  may  revolve  around  this  central  pivot.  On  the  upper 

plate  are  inserted  pieces  of  steel  rails 
at  right  angles,  and  in  the  manner  indi- 
cated in  Fig.  76.  The  turntable  is 
sometimes  provided  with  brakes  to  keep 
the  upper  plate  fixed  to  the  right  place, 
and  then  the  lower  plate  is  provided 
FlG-  76-  with  slots  to  receive  the  brake  which 

is  attached  to  the  upper  plate.  The  platform  of  the  turntable 
is  sometimes  made  of  wood,  but  in  any  case  the  ring  containing 
the  balls  acting  as  rollers,  as  well  as  the  casing  of  the  pivot,  are 
.always  made  of  steel. 

The  cars  designed  by  Decauville  for  industrial  railways  were 


HAULING    EXCAVATED    MATERIALS    ON   HORIZONTAL    ROADS.    159> 

built  of  iron  and  steel,  and  in  the  form  known  in  this  country  as 
tip-cars.  These  consist  of  a,n"iron  truck  with  steel-flanged  wheels 
of  about  18  ins.  diameter  fisgd  to  axles,  which  are  attached  to 
the  frame  of  the  truc'K  by  means  of  box-shaped  axles — boxes  some- 
times provided  with  springs.  At  both  ends  of  the  truck  there 
are  two  trusses  for  the  support  of  the  body  of  the  car.  These 
are  made  of  steel  and  are  supported  on  four  pivots,  two  on  each 
end  resting  on  the  trusses  and  so  arranged  as  to  have  the  center 
of  gravity  of  the  car,  when  loaded,  just  a  little  above  the  plane  of 
the  pivots  and  between  them.  Such  a  construction,  while  it 
prevents  the  overturning  of  the  cars  during  the  hauling,  allows- 
them  to  be  easily  unloaded  by  tipping,  hence  the  name  of  tip- 
cars.  The  efforts  of  any  ordinary  workman  will  cause  the  body 
of  the  car  to  turn  over  a  pair  of  pivots,  and  it  will  assume  then 


FIG.  77. 

the  position  indicated  in  Fig.  77,  and  the  material  will  automatic- 
ally descend  by  gravity  on  account  of  the  peculiar  shape  of  the 
car.  Figs.  77  and  78  represent  standing  and  unloaded  tip-cars 


160 


EARTH    AND    ROCK    EXCAVATION. 


for  industrial  railways  as  built  by  G.  L.  Stuebner  of  Long  Island 
City,  which  are  very  similar  to  those  built  by  Decauville. 

All  tip-cars  are  constructed  on  the  same  principle,  but  with 
different  arrangements  for  the  support  of  the  body  of  the  cars 
and  for  unloading;  these  are  covered  by  patents  controlled  by 
the  various  manufacturers.  The  capacity  of  the  cars  varies 
from  12  to  45  cu.  ft.,  but  cars  of  1  cu.  yd.  capacity  are  the  most 
convenient  for  ordinary  excavations.  The  height  of  the  body 
of  the  car  is  so  arranged  as  to  require  the  smallest  effort  in  loading 


it,  and  to  allow  the  easy  propulsion  of  the  car  either  by  hand  or 
by  other  motive  power.  Attached  to  the  frames  of  the  trucks  there 
.are  bumpers,  chains,  and  hooks  in  order  that  several  cars  may  be 
formed  into  trains.  Some  cars  must  be  also  provided  with  hand- 
brakes which  are  placed  on  a  small  platform  on  the  rear  of  one  of 
the  trusses  supporting  the  body  of  the  car. 

Side-dumping  tip-cars  are  most  commonly  employed,  but  cars 
.are  also  constructed  which  dump  at  the  front  and  back.     These 


HAULING    EXCAVATED    MATERIALS    ON    HORIZONTAL    ROADS.    161 

are  similar  to  the  side-dumping  cars  described  above,  the  only 
difference  being  that  the  frarnes  supporting  the  body  of  the  car, 
instead  of  being  placed  at  thejront  and  rear  end  of  the  truck,  are 
located  along  its  two  sicles.  Tip-cars  are  used  for  carrying  earth  or 
stones,  but  in  case  larger  stones  are  to  be  carried  platform  cars  as 
indicated  in  Fig.  79  are  found  to  be  more  convenient. 

The  advantage  of  industrial  railways  is  that  they  may  be 
operated  by  any  motive  power,  either  animal  or  mechanical.  The 
total  resistance  of  an  ordinary  tip-car  hauled  on  a  horizontal 


FIG.  79. 

road  can  be  assumed  at  15  Ibs.  per  ton  and  the  resistance  increases 
in  the  ratio  of  4  Ibs.  per  TV-in.  grade  per  foot.  Industrial  railways, 
although  laid  on  horizontal  roads,  on  account  of  the  undulations 
of  the  road-bed  can  be  considered  as  laid  on  ^-in.  grade  and  then 
the  total  resistance  of  a  tip-car  will  be  35  Ibs.  per  ton.  The  ordinary 
capacity  of  these  tip-cars  varying  between  20  and  45  cu.  ft.,  the 
total  weight  of  their  loads  will  vary  from  2000  to  4500  Ibs.  and 
the  resistance  to  traction  will  therefore  vary  from  29.16  to  65.6  Ibs. 
Since  the  weight  that  any  ordinary  laborer  can  support  walking 
3  ft.  per  second  can  be  considered  as  varying  from  50  to  60  Ibs.,  it 
is  easily  seen  that  any  laborer  can  move  a  loaded  tip-car,  especially 
if  it  is  not  of  the  largest  dimensions. 


162  EARTH  AND  ROCK  EXCAVATION. 

The  working  power  of  a  horse  is  considered  as  five  times  greater 
than  that  of  a  man,  and  consequently  a  single  horse  can  easily 
haul  a  train  composed  of  not  less  than  five  tip-cars  and  even  a 
greater  number,  according  to  their  capacity.  Horses  employed 
as  motive  power  on  industrial  railways  give  efficient  results  for 
distances  not  greater  than  1  mile;  for  greater  distances,  however, 
the  employment  of  a  small  locomotive  is  found  to  be  more  eco- 
nomical. 

Industrial  railways  should  form  an  essential  part  of  any  con- 
tractor's plant.  The  writer  has  had  the  opportunity  to  employ 
them  several  times,  and  in  different  countries  and  under  entirely 
different  circumstances  they  have  always  given  most  satisfactory 
results.  From  his  own  4  experience  the  writer  can  certify  that 
industrial  railways  afforcftinost  economical  means  of  transportation 
for  excavated  materials  within  about  1-mile  distances. 

In  the  transportation  of  excavated  materials,  narrow-gauge 
railways  are  more  commonly  employed  than  the  industrial  railways 
just  described.  This  is  chiefly  due  to  the  adaptability  of  these 
roads  to  any  locality  and  all  distances  and  also  because  the  trains 
may  be  hauled  either  by  horses  or  by  steam-locomotives.  In 
general,  these  roads  are  convenient  for  the  transportation  of  not 
less  than  20,000  cu.  yds.  of  earth  and  the  trains  can  be  advanta- 
geously hauled  by  horses  to  a  distance  of  3000  ft.,  but  for  longer 
distances  steam-locomotives  will  give  better  results.  These  limits, 
however,  do  not  apply  to  every  case,  but  give  in  a  general  way  an 
idea  of  the  limitations  of  the  various  methods  of  hauling.  All 
the  particular  conditions  of  the  work  and  locality  should  be  accu- 
rately examined  before  deciding  upon  the  most  convenient  road 
and  method  of  hauling  to  be  used. 

The  road  of  narrow-gauge  railways  temporarily  built  for  the 
transportation  of  the  material  consists  of  light  rails  of  from  16  to 
24  Ibs.  per  yard,  fixed  to  the  ties  by  means  of  iron  spikes  just  as 
in  ordinary  railroads.  The  various  sections  of  rails  are  made 
continuous  by  means  of  fish-plate  joints.  According  to  the 
traffic  and  also  the  cars  at  hand,  the  gauge  of  the  track  is  usually 
made  2,  2£,  or  3  ft.  The  ties  are  made  of  square  timbers  6X6  ins. 


HAULING    EXCAVATED   MATERIALS    ON   HORIZONTAL    ROADS.    163 


and  5  ft.  long  and  they  are  spaced  about  2  ft.  center  to  center. 
The  road  is  provided  with,  curves,  switches,  turnouts,  crossings, 
etc.,  just  as  any  ordinary  rajlroad  would  be. 

It  is  necessary,  fiowever,  to  remark  that  in  earthworks  the 
narrow-gauge  road  being  constructed  either  on  top  of  the  newly 
built  embankment  or  on  the  bottom  of  the  pits  or  trenches  is 
liable  to  settle  under  the  weight  of  the  traffic,  and  consequently 
it  will  be  necessary  to  have  a  special  gang  exclusively  employed 
in  maintaining  it.  The  construction  of  the  road  is  very  expensive 
when  compared  with  industrial  railways.  As  a  rule  it  can  be 
assumed  that  it  will  take  twenty  days'  work  for  a  man  to  build 
one  mile  of  narrow-gauge  road,  so  that  the  cost  per  mile  will 
be  $30.  At  least  two  men  per  mile  should  be  employed  for 
repairing,  and  this  will  cost  $3  per  day  per  mile  of  road. 

As  a  rule,  the  cars  employed  on  these  roads  are  self-dumping. 
The  cars  can  be  divided  into  two  groups,  according  to  the  manner 
in  which  they  are  dumped,  whether  on  one  side  or  on  all  sides. 
Whatever  their  form  may  be  they  are  always  composed  of  a  four- 
wheeled  truck,  upon  which  rest  the  various  devices  supporting 
the  box  containing  the  excavated  materials.  They  are  built  of 
different  sizes  and  shapes.  One  of  the  simplest  forms  of  dumping- 
car  is  the  one  illustrated  in  the  diagram  (Fig.  80).  This,  as  usual, 


FIG.  80. 


is  composed  of  an  ordinary  four-wheeled  truck,  upon  which  rests 
a  wooden  frame  of  trapezoidal  shape  with  the  longer  side  on  the 


164 


EARTH    AND    ROCK    EXCAVATION. 


truck  and  the  small  one  on  top  supporting  the  body  of  the  car. 
This  is  hinged  to  the  frame  and  when  loaded  is  kept  in  place  by 
means  of  vertical  props  resting  on  the  truck  and  holding  the  edge 
of  the  box  which  does  not  rest  on  the  wooden  frame.  When 
the  car  is  loaded  the  center  of  gravity  remains  very  close  to  the 
line  of  the  edge  of  the  trapezoidal  wooden  frame,  so  that  after 
the  vertical  supports  have  been  removed,  a  laborer  with  a  very 
small  effort  will  .turn  the  body  of  the  car  around  the  hinged  axis 


FIG.  81. 

'and  the  box  will  take  a  position  following  the  sloping  side  of  the 
trapezium.  If  the  board  along  the  side  of  the  car  has  been  pre- 
viously removed,  the  earth  will  fall  to  the  ground. 

On  the  same  principle  is  constructed  the  Western  Dump-car 


HAULING    EXCAVATED    MATERIALS    ON   HORIZONTAL    ROADS.    165 

illustrated  in  Fig.  81,  which  has  the  great  advantage  over  the 
one  just  described  that  it  can  be  dumped  on  either  side.  In  this 
case  also  the  car  is  compose^!  of  a  four-wheeled  truck  provided 
with  an  additional  longitudinal  centerpiece  upon  which  rest  the 
cast-iron  stands  supporting  the  body  of  the  car.  As  is  clearly 
shown  in  the  figure,  these  stands  are  pin-connected  so  that  the 
car  may  revolve  on  either  side.  The  box  is  kept  horizontal  by 
means  of  chains  tying  it  to  the  truck.  By  loosing  one  of  the 
chains  and  with  a  very  small  effort  any  laborer  can  easily  tilt 
the  car,  which  will  overturn  in  the  opposite  direction,  thus  unload- 
ing the  material.  The  chain  fastenings  can  be  released  by  the 
foot  and  the  car  dumped  while  in  motion.  The  sideboards  of 
these  cars  work  automatically,  opening  on  the  side  on  which  the 
dumping  is  done  and  closing  as  soon  as  the  car  is  returned  to  an 
upright  position.  These  cars  are  built  of  different  sizes,  from 
1£  cu.  yds.  to  5  cu.  yds.  capacity.  Another  type  of  dumping-cars 
used  in  connection  with  narrow-gauge  railway  are  rotary  dump- 
ing-cars, which  may  unload  the  material  not  only  on  both  sides 
like  those  just  described,  but  also  in  front  and  back.  Such  an 
arrangement  is  very  convenient  for  building  embankments  in 


FIG.  82. 

which  the  cars  must  be  unloaded  at  the  front  of  the  slope.  There 
is  a  large  variety  of  these  cars,  and  all  of  them  are  constructed 
on  the  same  principle.  In  the  center  of  a  four-wheeled  truck 
there  is  a  circular  iron  platform  to  which  is  pivoted  another  simi- 
lar one  attached  to  the  bottom  of  the  body  of  the  car,  so  that  it 
mav  revolve  around  its  center.  If  the  car  is  provided  with  a 


166  EARTH  AND  ROCK  EXCAVATION. 

dumping  arrangement,  it  can  be  unloaded  in  any  position.  Fig. 
82  shows  the  Western  Rotary  Dump-car.  This  is  provided  with 
a  pivoted  or  swinging  draw-bar,  which  is  pushed  aside  when 
dumping  over  the  end,  so  that  a  much  steeper  angle  is  made  in 
dumping  than  if  it  were  necessary  to  dump  over  the  draw-bar. 
The  same  automatic  device  for  the  end-board  is  used  on  the  rotary 
car  as  is  used  on  cars  dumping  sideways. 

All  dumping-cars,  whatever  their  form  may  be,  are  usually 
hauled  in  trains.  They  must  be  provided  with  'bumpers  and 
chains  and  other  connections  similar  to  but  simpler  and  of  smaller 
dimensions  than  are  used  in  ordinary  railroad  cars. 

The  motive  power  used  in  hauling  the  trains  is  either  horses 
or  steam-locomotives.  Having  discussed  traction  by  horses  in 
other  parts  of  this  book,  it  will  be  proper  to  devote  here  a  few 
words  to  locomotives.  These  are  specially  constructed  for  this 
kind  of  work,  are  very  light,  and  economical  both  in  cost  and  in 
running  expenses,  and  are  constructed  of  different  shapes  by 
various  manufacturers. 

Fig.  83  shows  a  four-coupled  locomotive  built  by  the  Baldwin 
Locomotive  Works  of  Philadelphia,  Pa.,  for  the  Colorado  Fuel  and 


FIG.  83. 

Iron  Company.  It  was  built  to  run  on  a  3-ft.  gauge  and  its  total 
weight  was  20  tons.  Its  principal  dimensions  were:  Diameter 
of  cylinder,  12  ins.;  length  of  stroke,  16  ins.;  distance  between 
driving-wheels,  5  ft. 


HAULING    EXCAVATED    MATERIALS    ON    HORIZONTAL    ROADS.    167 

The  quantity  of  coal  consumed  varies  with  the  locomotive; 
on  the  average  it  may  be  assumed  that  it  consumes  about  6  Ibs. 
of  coal  per  horse-power  per  Hour.  The  quantity  of  water  about 

gallons  per  mile.  The  tractive  power  of  a  locomotive,  accord- 
ing to  Trau  twine,  is  given  by  the  following  formula: 


Square  of  diameter  of  v  Single  length  of    Aven«e  «tean? 

one  piston  in  inches  X  strokes  in  ins.   X   sur,e.  m  the  «* 

r  in  Ibs.  per  sq.  inch 

Diameter  of  driving-wheel  in  inches 

The  cost  of  hauling  1  cu.  yd.  of  earth  by  means  of  steam-loco- 
motives is  given  by  dividing  the  daily  running  expenses  by  the 
total  quantity  of  the  hauled  materials.  The  daily  running  ex- 
penses are  given  by  the  consumption  of  coal,  water,  and  lubri- 
cants, and  the  wages  of  the  engineer  in  charge  of  the  locomotive. 
Coal  and  water  vary  with  the  distance  run,  while  the  wages  of 
the  engineer  remain  fixed.  Assuming  that  a  locomotive  will 
travel  100  miles  per  day  carrying  1000  cu.  yds.  of  earth  to  the 
dumping  place,  the  cost  of  hauling  a  unit  of  volume  will  be  as 
follows  : 

Coal  .........................  $4.00 

Water  .......................     1.00 

Oil,  etc..  ;  ....................  80 

Engineer  .....................     3.50 


Total  daily  expenses $9.30 

r\       i.-A '     f      AI.  i,     i   j  •       j          '  Ann  =0.009  ct.  per  cu.  yd.. 
Quantity  of  earth  hauled  in  a  day . .   1000 

or  nearly  1  cent  per  cubic  yard.  Other  items  should  be  added 
that  will  greatly  increase  the  cost  of  hauling  the  unit  of  volume 
of  the  material.  These  are,  for  instance,  the  wages  of  the  laborers 
employed  in  repairing  the  road,  the  interest  of  the  invested  capi- 
tal, the  repairs  to  locomotive  and  cars,  which  is  not  a  small  item, 
the  sinking  fund,  and  the  superintendence. 

When  a  very  large  quantity  of  material  has  to  be  excavated 
in  a  short  time,  and  the  distance  to  where  the  materials  are  to 
be  deposited  is  large,  it  will  be  more  convenient  to  employ  loco- 


168  EARTH  AND  ROCK  EXCAVATION. 

motives  of  greater  efficiency  running  on  standard-gauge  tracks. 
In  such  cases  the  excavation  is  made  by  several  powerful  machines, 
and  they  must  be  served  by  a  continuous  procession  of  cars  of 
large  capacity.  The  trains  are  formed  of  several  cars  heavily 
loaded,  and  consequently  it  is  necessary  to  use  a  tractive  force 
of  great  efficiency. 

The  standard-gauge  road  is  built  with  rails  and  ties  of  the 
same  dimensions  used  in  ordinary  railroads,  and  is  constructed 
in  the  same  way.  In  case  the  work  will  not  last  for  many  years, 
it  will  be  more  convenient  to  employ  second-hand  material  both 
for  the  rails  and  ties  instead  of  buying  new.  It  will  cost  a  great 
deal  of  money  to  keep  the  track  in  working  order,  since  the  weight 
of  the  locomotives  and  loaded  cars  will  tend  to  sink  the  track, 
especially  if  located  on  top  of  recently  constructed  embankments 
or  in  the  bottom  of  the  open  trenches.  This  is  an  important  item" 
that  will  greatly  increase  the  cost  of  hauling,  and  it  should  not 
be  forgotten. 

The  locomotives  employed  are  of  the  railroad  type,  either 
with  water- tank  and  fuel-bunker  mounted  on  the  locomotive,  or 
carried  by  a  separate  tender  as  on  ordinary  railroads.  Since 
heavy  locomotives  are  very  expensive,  it  will  be  perhaps  conve- 
nient to  get  some  of  those  discarded  by  railroads  for  ordinary 
traffic.  But  the  advantage  of  using  second-hand  material  will 
depend  upon  the  amount  of  the  earth  to  be  hauled,  the  magnitude 
of  the  work,  and  the  time  in  which  the  work  is  to  be  completed. 
Locomotives,  as  a  rule,  are  discarded  by  the  railroad  companies 
when  the  yearly  expenses  for  repairing  required  to  keep  them 
in  working  order  are  very  heavy.  In  such  a  case,  and  especially 
when  the  work  will  last  for  several  years,  it  will  not  be  convenient 
to  get  discarded  locomotives,  but  to  use  new  ones  of  lighter  effi- 
ciency. 

The  cars  used  in  the  excavation  are  of  three  different  types — 
the  platform,  the  gondola,  and  the  dumping  cars.  Platform  cars 
are  the  simplest  and  the  most  commonly  employed  cars  for  haul- 
ing earth  excavated  by  machines.  They  are  34  ft.  long  and  7  ft. 
wide,  and  when  loaded  they  contain  almost  10  cu.  yds.  of  earth. 


HAULING    EXCAVATED    MATERIALS    ON   HORIZONTAL    ROADS.    169 

They  consist  of  a  heavy  platform  of  hard  wood  supported  on  a 
double  four-wheeled  truck.  >Around  the  edges  of  the  long  sides 
of  the  platform  there  are  iron^yes  to  receive  short  vertical  posts 
which  guide  the  unloading  apparatus.  At  one  end  the  cars  are 
provided  with  a  hinged  apron  made  of  sheet  steel  as  wide  as  the 
whole  width  of  the  car,  and  of  such  a  length  as  to  abut  on  the  next 
car,  thus  bridging  the  empty  space  between  the  two  consecutive 
cars,  and  allowing  a  continuous  support  to  the  unloader,  whose 
description  is  given  on  p.  326. 

The  other  type  of  car  used  to  haul  excavated  earth  is  the 
ordinary  gondola  car.  This  is  similar  both  in  construction  and 
dimensions  to  the  platform  car,  with  the  difference  that  all  around 
the  edges  there  is  a  3-ft.-high  strong  board  to  retain  the  materials. 
It  is  very  convenient  for  the  transportation  of  materials  to  a 
great  distance,  since  each  car  may  transport  over  25  cu.  yds.  of 
material  at  a  time.  But  it  must  be  unloaded  by  hand,  and  this 
is  an  expensive  item  to  be  added  to  the  unit  of  cost  of  the  mate- 
rial. The  relative  convenience  of  employing  the  gondola  instead 
of  the  platform  cars  is  obtained  by  an  accurate  comparison  of  all 
the  items  of  cost  in  both  cases;  the  greater  number  of  cars  and 
locomotives  but  the  inexpensive  unloading  in  one  case  versus  the 
smaller  number  of  cars  and  locomotives  together  with  the  costly 
unloading  in  the  other  case. 

The  other  type  of  car  used  in  the  transportation  of  excavated 
material  is  the  dumping-car.  There  is  a  large  variety  of  them  on 
the  market,  all  covered  by  patents,  which  the  manufacturers  claim 
afford  great  advantages.  Those,  however,  used  by  contractors 
are  only  of  two  kinds — one  with  a  very  limited  usefulness,  while 
the  other  car  is  growing  in  favor  because  it  can  unload  the  material 
where  it  is  needed.  The  simplest  dumping-car  is  the  one  used  by 
railroads  for  carrying  coal.  It  is  mounted  on  a  double  four- 
wheel  truck,  and  is  in  the  shape  of  a  trough  with  the  interior 
sloping  down  toward  the  bottom,  where  it  is  provided  with  a 
trap-door.  By  opening  this  the  material  will  descend  by  gravity 
and  the  car  be  unloaded.  These  cars,  however,  discharge  their 
contents  between  the  track,  and  they  can  be  employed  only  when 


170 


EARTH    AND    ROCK    EXCAVATION. 


the  dumping  is  effected  on  trestles,  otherwise  the  material  depos- 
ited within  the  rails  will  obstruct  the  traffic  of  the  road.  Con- 
sequently their  utility  is  very  small,  and  it  will  not  be  advisable 
for  the  contractors  to  use  them  except  in  the  case  of  dumping 
from  trestles  and  when  the  rolling  stock  may  be  provided  or 
loaned  by  the  railroad  company. 

More  convenient  are   the  Goodwin  dump-cars,  illustrated  in 
Fig.  84.     Notwithstanding  that  these  have  been  introduced  only 


.FIG.  84. 

a  few  years,  they  have  met  with  the  greatest  success,  and  are 
already  extensively  used  by  contractors,  railroads,  and  mining 
companies.  They  are  constructed  entirely  of  steel,  and  are  divided 
into  two  compartments  which  can  be  unloaded  separately,  the 
division  being  made  by  a  steel  diaphragm.  The  advantages  of 
these  cars  are  given  by  the  manufacturers  as  follows:  (1)  That, 
on  account  of  their  peculiar  construction,  they  discharge  all  kinds 
of  material  hauled  as  freight,  using  the  gravity  of  the  material 
alone  as  the  unloading  power.  (2)  That  the  discharging  appa- 
ratus can  be  released  by  compressed  air,  steam,  electricity,  or 
hand-power  at  will.  (3)  That  they  can  be  discharged  on  either 


HAULING  EXCAVATED  MATERIALS  ON  HORIZONTAL  ROADS.  171 

or  both  sides,  or  in  the  center,  According  to  the  different  manners 
indicated  in  the  diagram  (Fi^.  85),  and  yet  without  careening  or 
moving  of  the  body  of  4he  car.  ^(4)  That  a  train  of  Goodwin  cars 
or  one  car  can  be  discharged  with  perfect  safety  while  running  at 


FIG.  85. 

any  speed,  and  the  valves  (floor)  need  not  be  replaced  until  the 
car  reaches  the  loading  station.  (5)  If  the  cars  are  discharged 
while  running,  they  will  spread  the  load  from  5  to  30  ft.  from  the 
track;  the  width  of  " spread"  being  regulated  by  the  speed  of  the 
train.  (6)  That  one  man  in  any  part  of  the  train  can  discharge 
the  loads  from  all  or  any  number  of  cars  in  the  train  simultaneously. 


CHAPTER  XIII. 

METHODS  OF  HAULING  EXCAVATED  MATERIALS  ON  INCLINED 

ROADS. 

THE  methods  of  hauling  excavated  materials,  so  far  described, 
can  be  employed  only  on  roads  with  a  grade  less  than  8  or  10  per 
cent,  when  wheelbarrows,  carts,  wagons,  and  scrapers  are  used, 
or  on  roads  whose  inclination  is  not  greater  than  3  per  cent,  when 
the  materials  are  hauled  on  cars  running  on  tracks.  But  in  many 
cases,  on  account  of  configuration  of  the  ground,  and  especially 
in  carrying  earth  from  borrow-pits  to  the  embankment,  it  will  be 
almost  impossible  to  develop  roads  with  such  a  small  gradient, 
and  then  engineers  and  contractors  must  provide  inclined  roads. 

A  primary  division  of  the  various  means  of  hauling  materials 
by  means  of  inclined  roads  can  be  made  according  to  whether 
the  materials  are  hauled  up  or  down  grade.  The  devices  for 
hauling  materials  up  grade  are  so  many  and  of  such  different 
shapes  that  it  is  very  difficult  to  give  the  details  of  each  one,  and 
here,  therefore,  only  the  most  important  will  be  described  to 
illustrate  the  principles  upon  which  they  are  constructed.  The 
Chicago  Drainage  Canal  was  a  work  of  great  magnitude  in  which 
all  the  materials  excavated  on  the  bottom  of  the  canal  were  raised 
up  and  deposited  on  the  spoil-banks  along  the  edges,  and  many 
different  methods  of  hauling  the  materials  up  inclines  were  em- 
ployed by  the  contractors.  The  details  of  these  machines  are  found 
in  Chas.  S.  Hill's  book,  The  Chicago  Main  Drainage  Channel^ 
published  by  the  Engineering  News  Publishing  Co.,  which  can 
be  advantageously  consulted  for  more  information.  To  haul  mate- 
rials down  steep  inclines  is  a  much  simpler  affair,  and  it  is  usually 
done  by  means  of  gravity  roads. 

172 


HAULING    EXCAVATED    MATERIALS    ON    INCLINED    ROADS.      173 

Inclines  for  Wheelbarrows. — When  the  hauling  is  done  by 
means  of  wheelbarrows  and  the  earth  from  the  bottom  of  a  borrow- 
pit  must  be  raised  tathe  torAf  an  embankment  under  such  con- 
ditions that  no  road  can  be  stretched  between  these  points,  the 
simplest  manner  of  overcoming  the  difference  of  level  is  by  means- 
of  tied  barrows.  This  consists  in  hauling  the  materials  on  wheel- 
barrows passing  over  a  plank  road  inclined  according  to  the  slope 
of  the  cut,  and  just  wide  enough  to  allow  the  passage  of  two  wheel- 
barrows in  opposite  directions.  A  rope  is  placed  along  one  side 
of  the  plank  road  and,  passing  through  a  horizontal  sheave  at  the 
top  of  the  incline,  returns  on  the  other  edge  of  the  plank  road. 
At  each  end  of  the  rope  is  attached  a  wheelbarrow.  The  laborer 
descending  with  the  empty  barrow  will  assist  the  ascent  of  the 
other  man,  who  is  pushing  the  loaded  barrow  up  the  incline. 

When  the  inclination  of  the  slope  is  greater  and  consequently 
too  much  effort  will  be  required  to  push  the  wheelbarrow  up  the 
plank  road,  animal  power  may  be  advantageously  employed. 
In  such  a  case,  at  a  convenient  distance  from  the  edge  of  the  slope 
is  placed  a  vertical  post  (Fig.  86)  provided  with  two  sheaves.  A 


FIG.  86. 

rope  with  one  end  attached  to  a  wheelbarrow  in  the  bottom  of 
the  excavation  passes  over  the  upper  sheave  and  assumes  a  hori- 
zontal position  by  passing  around  the  lower  sheave.  At  the 
other  end  of  the  rope  a  horse  is  hitched,  and  in  moving  pulls  the 


174  EARTH  AND  ROCK  EXCAVATION. 

rope,  thus  causing  the  ascent  of  the  wheelbarrow  up  the  plank 
road.  It  is  convenient  to  build  the  incline  higher  than  the  top 
of  the  slope,  and  ending  with  a  platform  under  which  may  pass  a 
car  or  wagon  into  which  the  excavated  materials  are  dumped. 
Fig.  86  clearly  indicates  this  manner  of  hauling  materials  up 
inclines.  It  was  employed  in  the  construction  of  the  London  & 
Birmingham  Railway;  on  some  branches  of  the  Paris,  Lyon  & 
Mediterranean  Railway  in  France,  and  more  recently  on  the  St. 
Gothard  line. 

The  work  done  by  means  of  wheelbarrows  is,  as  a  rule,  slow  and 
expensive,  and,  on  account  of  the  great  improvement  in  hoisting- 
machines  in  the  last  few  years,  this  simple  method  of  hauling 
excavated  materials  up  the  inclines  is  very  seldom  employed. 
But  in  some  particular  cases,  as,  for  instance,  when  along  the  line 
of  the  road  there  is  a  small  isolated  embankment  to  be  constructed 
from  the  material  excavated  in  a  borrow-pit,  this  slow  and  ancient 
method  may  still  be  found  convenient. 

Inclines  for  Carts  and  Wagons. — To  overcome  the  sharp  dif- 
ference of  level  existing  between  the  ground-surface  and  the 
bottom  of  the  excavation,  when  the  earth  is  removed  by  carts 
:and  wagons,  inclines  are  made  of  earth  left  in  place.  Another 
team  of  horses  hitched  to  the  shafts  of  the  carts  will  facilitate  the 
moving  of  the  vehicles  up  the  incline.  When  the  remainder  of 
the  excavation  is  completed  these  inclines  are  removed  by  cut- 
ting them  down  until  they  become  so  sharp  that  vehicles  cannot 
pass,  and  then  they  are  cut  and  removed  by  hand,  working  in 
benches,  until  the  vertical  side  of  the  excavation  is  obtained. 
This  manner  of  hauling  excavated  materials  is  commonly  em- 
ployed by  cellar-diggers  in  every  city. 

When  the  work  of  excavation  is  of  such  importance  that  many 
cars  have  to  be  hauled  every  day,  and  when  the  length  of  the 
haul  is  so  great  that  more  than  one  team  has  to  be  employed  in 
helping  the  carts  surmount  the  incline,  hauling  the  carts  by  steam- 
power  will  be  found  more  convenient.  In  such  a  case  a  single- 
drum  reversible  engine  with  a  wire  rope  coiled  around  the  drum 
will  be  placed  on  top  of  the  incline.  The  end  of  the  rope  is  pro- 


HAULING    EXCAVATED    MATERIALS    ON    INCLINED    ROADS.      175 

vided  with  a  hook  which  engages  the  ring  at  the  head  of  the  shaft 
of  the  wagon  standing  at  the^  foot  of  the  incline.  By  turning  the 
engine  the  wire  ropS  will  coil  around  the  drum,  thus  pulling  up 
the  incline  the  carts  and  wagons  together  with  the  horses,  which 
will  walk  easily,  being  relieved  of  the  load.  An  empty  car  going 
down  the  incline  will  carry  the  rope  to  the  bottom  of  the  excava- 
tion, so  as  to  be  attached  to  a  loaded  cart.  By  this  method  the 
writer  has  seen  from  12  to  15  cars  per  hour  hauled  up  an  incline 
100  ft.  long  and  20  ft.  high;  for  ordinary  calculations  it  can  be 
assumed  that  one  car  every  five  minutes,  or  12  per  hour,  can  be 
hauled,  making  an  average  of  100  carts  per  day. 

When  the  excavated  materials  are  removed  by  means  of  tip- 
cars  hauled  by  horses  and  running  on  light,  narrow-gauge  tracks, 
the  difference  of  level  between  the  bottom  of  the  excavation  and 
the  top  of  the  embankment  is  usually  overcome  by  means  of  plank 
roads  similar  to  those  employed  in  connection  with  wheelbarrows. 
In  such  a  case,  however,  two  plank  roads  are  built  parallel  to  each 
other,  and  at  some  distance  apart,  and  are  provided  with  tracks 
similar  to  those  employed  throughout  the  work.  A  rope  is 
stretched  along  the  plank  roads  and  it  assumes  the  horizontal 
position  on  top  of  the  incline  and  in  the  space  between  the  two 
roads  by  passing  through  sheaves  placed  horizontally.  To  the 
horizontal  portion  of  the  rope  is  hitched  a  horse  which  by  moving 
in  one  direction  causes  the  ascent  of  a  tip-car  tied  to  one  end  of 
the  rope  and  the  descent  of  another  car  tied  to  the  other  extreme. 
This  operation  is  reversed  when  the  horses  move  in  the  opposite 
direction. 

This  manner  of  hauling  is  not  the  most  economical,  but  it  can 
be  usefully  employed  in  certain  special  cases,  as,  for  instance, 
when  all  the  hauling  is  done  by  means  of  cars  moved  by  horses 
on  a  temporary  narrow-gauge  road  and  the  embankment  built 
with  materials  taken  from  borrow-pits  is  not  very  large;  when 
the  work  is  done  in  localities  in  which  labor  is  cheap,  or  when  the 
work  is  so  located  that  the  economy  obtained  from  the  employ- 
ment of  mechanical  power  will  not  compensate  the  expense  of 
transporting  and  setting  up  a  mechanical  plant. 


176  EARTH  AND  ROCK  EXCAVATION. 

The  quantity  of  materials  hauled  in  this  manner  varies  from 
60  to  75  cu.  yds.  per  day.  For  such  an  output  two  horses  and 
drivers  and  four  laborers,  one  at  each  end  of  the  inclined  roads, 
are  required.  If  $5  be  the  daily  cost  of  hiring  the  two  horses  and 
their  drivers,  and  $5  is  paid  the  laborers,  the  cost  of  hauling  1  cu. 
yd.  of  material  will  vary  between  14  and  18  cents. 

Animal  power  is  not  advantageous  when  the  quantity  of  the 
earth  to  be  raised  is  large  and  when  the  capacity  of  the  cars  is  not 
less  than  1  cu.  yd.  In  such  cases  it  will  be  necessary  to  use  steam- 
power.  The  simplest  way  of  hauling  cars  by  steam  is  to  build  an 
inclined  road  supporting  trucks  connected  with  those  at  the  top 
of  the  embankment  and  at  the  bottom  of  the  excavation.  At  a 
convenient  distance  from  the  top  of  the  incline  is  located  a  single- 
drum  reversible  hoisting-engine.  The  hoisting  rope  coiled  around 
the  drum  is  provided  with  a  hook  at  its  free  end.  At  the  lower 
end  of  the  incline  a  train  is  formed  by  uniting  together  3,  4,  or  5 
cars,  and  the  hook  of  the  hoisting  rope  is  fastened  to  the  first  car. 
By  putting  the  engine  into  gear,  the  cable  will  coil  around  the 
drum,  thus  causing  the  cars  to  ascend  the  incline.  Reaching  the 
top  of  the  embankment  the  cars  are  shifted  onto  the  spoil-tracks 
and  the  materials  dumped  in  the  required  place.  The  descent  of 
the  empty  cars  is  accomplished  in  exactly  the  same  way;  a  train 
is  formed  and  to  the  rear  end  of  the  last  car  is  attached  the  hook 
of  the  cable.  The  engine  is  then  reversed  and,  on  loosing,  the 
cable  will  lower  the  cars  down  the  incline,  thus  preventing  their 
rushing  down  at  great  speed. 

This  manner  of  hauling  is  very  commonly  employed  in  works 
of  any  magnitude.  It  was  employed  on  some  sections  of  the 
Chicago  Drainage  Canal,  where  full  trains  were  hauled  at  once 
to  the  spoil-banks,  and,  more  recently,  it  has  been  used  on  Section 
13  of  the  New  York  rapid-transit  road  to  haul  to  the  surface 
the  materials  excavated  in  the  tunnel  north  of  157th  Street  along 
Broadway;  there,  however,  only  one  car  at  a  time  was  hauled, 
a  curve  being  provided  at  the  top  of  the  incline  where  the  cars 
were  shifted  and  side-tracked  until  a  train  was  formed  and  hauled 
to  the  dumping  place  by  a  dummy-engine. 


HAULING    EXCAVATED    MATERIALS    ON    INCLINED    ROADS.      177 

The  efficiency  of  this  method  of  hauling  depends  upon  the 
length  and  grade  of  the  inclines.  In  general  it  can  be  said  that 
from  500  to  600  cu.  yds.  of  material  can  be  hauled  up  in  a  day 
of  ten  working  hours. 

Hauling  by  Endless  Chain.  —  Another  method  of  hauling 
loaded  cars  up  inclines  is  by  means  of  an  endless  chain  or  wire 
rope.  The  incline  is  built  wide  enough  to  contain  a  double-track 
line,  one  track  being  used  for  the  ascending  cars  and  the  other 
track  for  the  descending  cars.  When  the  endless  chain  is  used 
this  passes  in  the  center  of  the  tracks  and  at  the  two  ends  of 
the  inclines  revolves  around  a  drum  provided  with  a  gear  whose 
teeth  grasp  the  links  of  the  chain.  If  one  of  the  drums  be  moved 
by  horse,  steam,  or  other  motive  power,  it  will  cause  the  chain 
to  travel  continuously  along  the  inclines,  and  the  cars  attached  to 
the  chain  will  ascend  one  of  the  inclines  and  descend  the  other. 
When  instead  of  a  chain  an  endless  rope  is  used,  no  gears  are 
required,  but  the  rope  is  wound  two  or  three  times  around  the 
lower  drum  so  as  to  cause  friction,  and  at  the  other  end  of  the 
incline  it  is  coiled  around  a  fly-wheel  moved  by  a  steam-engine. 
To  prevent  friction  of  the  chain  or  rope  in  its  travel  along  the 
inclines  it  is  supported  by  sheaves  placed  a  few  feet  apart  and 
between  the  rails  of  each  track. 

The  attachment  of  the  cars  to  the  endless  chain  can  be  very 
simply  made,  consisting  only  of  an  iron  bar  passing  through  the 
front  bumper  of  the  car  and  fitting  inside  the  link  of  the  chain. 
When  the  car  has  reached  the  upper  end  of  the  incline,  the  iron 
bar  is  lifted  and  the  connection  with  the  driving-chain  discon- 
tinued. A  better  and  safer  manner  of  connecting  the  cars  with 
the  chain  or  wire  rope  is  to  provide  the  driving-chain  or  rope  with 
buttons,  which  can  be  made  of  steel  wires  placed  every  20,  25,  or 
30  ft.  apart.  At  the  front  of -the  car  there  is  a  bar  ending  with 
an  inverted  U.  This  is  made  in  such  a  manner  that  it  allows 
the  passage  of  the  chain  but  not  the  buttons;  these  will  hold  fast 
the  cars  and  draw  them  up  the  incline.  By  raising  this  fork  the 
connection  with  the  driving  chain  or  rope  is  discontinued  and 
the  car  may  be  switched  to  the  tracks  leading  to  the  dumping 


178  EARTH  AND  ROCK  EXCAVATION. 

place.  Another  way  of  connecting  the  cars  to  the  driving  cable 
is  by  means  of  a  grip.  Such  an  expensive  arrangement  may  be 
found  useful,  perhaps,  in  continuous  works,  as  in  mines,  but  not 
in  temporary  works  such  as  earthwork  excavation,  and  any  further 
description  will  be  omitted. 

This  manner  of  hauling  cars  on  steep  roads  is  very  seldom 
employed  by  engineers  and  contractors  in  every-day  works  of 
excavation.  It  may  be,  however,  found  convenient  when  a  very 
large  quantity  of  material  has  to  be  hauled  and  conveyed  to  the 
spoil-banks  within  a  very  short  time.  In  such  a  case  the  condi- 
tions of  the  work  will  require  the  use  of  many  tracks  radiating 
from  the  ends  of  the  inclines  to  the  various  points  of  the  excava- 
tion and  dumping  grounds. 

The  average  velocity  of  the  driving  chain  or  rope  is  about  5  ft. 
per  second,  and  since  the  cars  may  follow  each  other  safely  at  a 
distance  of  60  ft.  apart,  the  efficiency  of  the  apparatus  will  be 
5  cars  per  minute  or  3000  cars  per  day.  In  practical  work  it  can 
be  assumed  at  1000  cars  of  1  cu.  yd.  capacity  and  consequently 
at  about  1000  cu.  yds.  per  day. 

Hauling  by  Traveling-cars. — The  cars  hauled  up  inclines  in 
the  various  ways  described  are  the  usual  dumping-cars  employed 
for  hauling  pur-poses  moving  on  narrow-gauge  tracks  on  horizontal 
roads.  They  have  been  employed  even  on  slopes  of  1  to  1,  with 
a  velocity  of  5  ft.  per  minute.  But  with  greater  velocity  and 
steeper  slopes  they  can  be  easily  overturned,  thus  causing  a  long 
delay  in  the  traffic  and  serious  trouble.  Then  instead  of  attach- 
ing the  cars  directly  to  the  hauling  cable,  it  is  more  convenient 
to  place  them  horizontally  on  a  platform  of  a  specially  constructed 
car,  which  is  hauled  up  the  incline  by  means  of  a  cable  coiled 
around  the  drum  of  a  reversible  hoisting-engine. 

This  special  car,  illustrated  in  Fig.  87,  consists  of  a  simple 
truck  in  which  the  front  and  rear  wheels  are  at  different  levels. 
The  platform  of  the  car  is  horizontal,  so  that  its  sides  are 
triangular  in  form,  and  is  provided  with  tracks  of  the  same 
gauge  used  throughout  the  work,  or  with  a  turntable  when 
the  material  to  be  hauled  converges  from  different  lines  and 


HAULING    EXCAVATED    MATERIALS    ON   INCLINED    ROADS.      179 

must  be  discharged  at  various,  points.  The  incline  is  built  lower 
than  the  plan  of  the  excavation,  in  order  that  the  tracks  on  the 
platform  of  the  car  may  be  flush  with  those  on  the  floor  of  the 


FIG.  87. 

excavation.  The  upper  end  of  the  incline  will  also  be  lower  than 
the  plane  of  the  rails  leading  to  the  spoil-banks. 

This  method  is  found  convenient  when  large  cars  are  used  for 
hauling  purposes,  and  it  is  employed  also  in  slopes  of  smaller 
inclination  than  those  indicated  above. 

Gravity  Roads. — So  far  only  the  cases  in  which  the  excavated 
materials  have  to  be  raised  from  the  bottom  of  a  pit  or  trench  up 
to  the  embankment  or  ground-surface  have  been  considered;  but 
there  are  also  cases  in  which  the  materials  in  order  to  reach  the  waste- 
banks  must  descend  an  inclined  road.  This  is  accomplished  by 
means  of  gravity  roads  in  which  the  loaded  cars  descending  by 
their  own  weight  on  an  inclined  road  haul  up  the  empty  ones. 
The  essential  parts  of  gravity  roads  are  chain  or  wire  rope  to 
which  the  cars  are  attached  and  a  drum  provided  with  a  brake 
to  regulate  the  speed  of  the  cars.  Around  this  drum  is  coiled  a 
portion  of  the  driving  rope.  The  attachment  forming  the  con- 
nection between  the  rope  and  the  cars  may  be  of  any  of  the  designs 
described  already  for  inclines  employed  in  hauling  up  materials. 

A  gravity  road  commanded  by  an  endless  chain  was  em- 
ployed at  the  Modane  portal  of  the  Mont  Cenis  tunnel  in  order 
to  carry  to  the  spoil-banks  the  materials  excavated  from  the 
front.  This  consisted  as  usual  of  two  parallel  tracks  laid  on  an 
incline.  In  the  middle  of  the  tracks  was  laid  a  chain  encircling  a 
driving  drum  at  the  top  of  the  incline  and  another  returning 
drum  at  the  foot  of  the  incline.  Along  the  incline  the  running 


180 


EARTH    AND    ROCK    EXCAVATION. 


of  the  chain  was  facilitated  by  means  of  rollers  placed  between 
the  tracks.  The  drums  were  provided  with  teeth  engaging  the 
links  of  the  chain. 

Gravity  roads  operated  by  wire  ropes  were  used  on  Section  13 
of  the  rapid-transit  railway,  where  the  earth  excavated  from 
tho  trenches  along  Broadway  was  carried  down  to  a  place  near 
the  Hudson  River  to  form  the  embankment  for  the  extension  of 
the  Riverside  Drive  to  Lafayette  Boulevard.  Various  methods 
were  employed  for  carrying  down  the  excavated  materials,  but 


FIG.  88. 


a  gravity  road  for  hauling  down  the  materials  loaded  into  the 
ordinary  Western  dumping-cars  was  built  at  144th  Street.  This  con- 
sisted of  a  double-track  line  of  3  ft.  gauge  placed  along  the  incline 
and  connected  with  switches  and  curves  to  the  line  running  along 


HAULING    EXCAVATED   MATERIALS    ON   INCLINED    ROADS.      181 

Broadway  and  parallel  to  the  cut.  The  device  for  regulating 
the  descent  of  the  cars  was  located  about  30  ft.  from  the  incline. 
It  consisted  (Fig.  88)  of  -two  grooved  wheels  4  ft.  in  diameter  and 
5  ft.  apart,  placed  longitudinally  and  with  the  axis  at  the  level  of 
the  ground.  The  wheels  had  flanges  surrounded  by  wooden 
brakes  similar  to  those  employed  in  hoisting-engines;  the  brakes 
were  commanded  by  handles  located  above  a  platform  in  a  small 
frame  building  where  the  operator  stood,  and  where  from  a  large 
window  he  could  command  a  view  of  the  whole  incline.  In  front 
of  this  frame  building  was  another  grooved  wheel  3  ft.  in  diameter, 
placed  transversely  and  higher  than  the  two  others.  A  wire  rope 
was  attached  to  the  descending  car,  passed  over,  and  was  wound 
around  one  of  the  longitudinal  wheels,  then  from  underneath  the 
first  wheel  passed  over  the  wheel  placed  transversely  and  from 
this  underneath  and  over  the  second  longitudinal  wheel  and  wras 
attached  to  the  empty  car  at  the  foot  of  the  incline.  In  this  man- 
ner the  descent  of  the  loaded  car  was  regulated  by  the  operator. 
The  road  worked  in  the  most  satisfactory  way  and  without  any 
accident.  Only  two  rollers  were  placed  between  the  tracks  at 
the  top  of  the  incline,  but  these  were  insufficient  since  the  rope 
made  grooves  in  the  ties  over  1  in.  deep. 

Belt  Conveyors.  —  Another  method  of  conveying  excavated 
materials  up  inclines  is  by  means  of  belt  conveyors.  These  con- 
sist in  depositing  the  materials  upon  an  endless  belt,  which  in 
traveling  carries  them  to  a  higher  distant  point.  The  belt  may 
travel  horizontally,  but  as  a  rule  it  moves  in  an  inclined  direction, 
and  is  more  commonly  employed  in  carrying  materials  up  to 
higher  points.  In  the  description  of  the  New  Era  grader  a  belt 
conveyor  was  used  for  loading  the  cars  and  formed  an  essential 
part  of  the  machine. 

A  belt  conveyor  is  made  up  of  several  parts — the  belt, 
the  runners,  and  the  driving  drum.  The  belt  must  be  of  such 
material  and  construction  as  not  to  be  easily  worn  out  by  the 
materials  that  it  carries;  the  runners  must  be  built  so  as  to  be 
perfectly  isolated  from  the  particles  of  the  carried  material,  other- 
wise they  will  be  clogged,  thus  preventing  the  running  of  the  belt ; 


182  EARTH  AND  ROCK  EXCAVATION. 

the  driving  drum,  which  is  usually  placed  at  the  bottom  of  the 
incline,  can  be  driven  in  different  ways  according  to  the  length 
of  the  conveyors.  Small  and  short  conveyors  can  be  directly 
driven  from  line  shafting.  In  larger  and  longer  conveyors  the 
driving  drum  can  be  driven  by  belt  from  line  shafting  running  at 
moderate  speed,  which  is  further  reduced  by  large  driven  pulleys 
on  a  head  shaft,  or  it  can  be  directly  driven  by  a  system  of  cog- 
wheels. 

Since  the  belt  of  these  conveyors  runs  continuously  they  give 
the  most  efficient  work  in  carrying  away  materials  excavated  by 
means  of  machines  working  continuously.  In  a  paper  read 
before  the  American  Society  of  Civil  Engineers,  July  2,  1888,  Mr. 
William  Plumb  Williams  thus  described  a  belt  conveyor  used  in 
connection  with  a  down-digging  machine  in  the  construction  of 
the  Panama  Canal: 

"'At  Tavanilla  in  connection  with  the  endless  chain  of  bucket 
excavator  was  employed  a  transporter.  A  truss  of  500  ft.  in 
length  was  supported  at  one  end  on  the  deck  of  the  excavator 
and  extended  at  right  angles  to  the  fore-and-aft  line  of  work,  the 
other  end  being  supported  upon  a  traveling  derrick  and  car. 
This  truss  was  6  ft.  in  width  and  10  ft.  in  height,  and  an  endless 
belt  4J  ft.  wide  received  motion  from  an  independent  engine  of 
the  excavator.  The  contents  of  the  buckets  of  the  excavator 
were  discharged  into  the  hopper  and  out  on  to  this  traveling  belt, 
thence  along  over  top  of  truss  until  the  end  was  reached,  when, 
the  belt  going  over  the  outer  tumbler,  its  contents  fell  to  the 
ground.  The  outer  end  of  the  truss  may  be  raised  as  high  as 
30  ft.  from  the  ground,  giving  room  for  a  large  bank  to  fall  with- 
out obstructing  the  passage  of  derrick  car  from  the  debris  sliding 
toward  the  machine. 

"In  this  work  the  excavator  was  digging  30  ft.  below  the 
rail  of  the  car;  material  was  carried  500  ft.  distant  and  elevated 
a  total  of  50  ft.  This  necessitated  the  keeping  up  of  three 
tracks — of  excavator,  a  track  of  platform  car  supporting  belt, 
engine,  and  boiler,  and  a  track  of  derrick  car.  In  addition 
to  the  regular  crew  of  the  excavator,  there  were  used  one  man  on 


HAULING    EXCAVATED  MATERIALS    ON    INCLINED    ROADS.      183 

the  derrick  car  to  preserve  a  constant  forward  motion  up  the 
track  with  the  excavator,  one  engineer  on  the  platform  car  to 
regulate  belt  engine,  and  one  f]*eman  each  on  derrick  car  and 
platform  car." 

Belt  conveyors  were  also  employed  in  hauling  the  materials 
excavated  from  the  bottom  of  the  canal  to  the  waste  banks  in 
the  construction  of  the  Chicago  Drainage  Canal,  and  were  de- 
signed by  Mr.  L.  W.  Bates  of  Chicago.  These  consisted  of  an 
endless  rubber  belt  22  ins.  wide,  passing  from  a  driving  station 
on  one  bank  of  the  canal  across  to  the  other  side,  along  a  truss 
over  the  spoil-bank  round  suitable  pulleys  at  the  further  end  of 
the  truss  and  back  again  to  the  power  station  on  the  opposite 
bank.  The  installation  on  each  side  was  mounted  on  tracks,  so 
that  it  could  be  advanced  as  the  work  progressed.  The  belt  was 
kept  loaded  by  a  steam-shovel  with  a  granulating  attachment, 
into  which  the  earth  was  delivered  and  reduced  to  a  suitable  con- 
dition before  being  discharged  upon  the  belt.  The  delivery 
capacity  varied  from  300  to  800  cu.  yds.  per  ten-hour  shift,  not 
a  high  duty.  A  writer  in  Engineering  commented  on  the  exten- 
sive character  of  the  plant  and  the  costly  labor,  since  it  required 
a  total  force  of  135,  about  half  of  whom  were  skilled  woikmen 
paid  from  $2  to  $3  a  day.  In  bad  weather  it  was  found  that  the 
belt  did  not  serve  the  purpose  of  conveying  efficiently,  and  only 
under  favorable  conditions  could  the  excavating  and  granulating 
machinery  be  worked  to  the  full  capacity. 

In  the  last  few  years  another  belt  conveyor  has  been  placed 
on  the  market,  and  has  found  a  very  considerable  employment  in 
public  works,  and  its  use  is  daily  extending.  It  is  the  Robins 
belt  conveyor  controlled  by  the  Robins  Conveying  Belt  Company 
of  New  York.  The  Robins,  'like  other  belt  conveyors,  is  composed 
of  the  three  essential  parts — the  endless  belt,  the  runners,  and 
the  driving  drums  at  the  end  of  the  incline.  The  belt  is  made  of 
canvas  covered  with  layers  of  rubber  thicker  at  the  center  than 
at  the  sides,  thus  protecting  the  belt  against  the  abrasion  of  the 
material  that  travels  upon  it.  The  runners,  or  idlers,  as  they  are 
called,  are  composed  of  three  cast-iron  cylinders  arranged  in  such 


184  EARTH  AND  ROCK  EXCAVATION. 

a  manner  so  as  to  form  a  trough,  thus  preventing  the  materials 
traveling  on  the  belt  from  fulling  on  the  sides  and  clogging  the 
runners.  Fig.  89  shows  the  arrangement  of  the  trough  idlers  in 


FIG.  89. 

the  Robins  conveyor,  and  also  the  runners  below  to  facilitate  the 
return  of  the  belt.  When  carrying  wet  and  muddy  material, 
which  easily  sticks  to  the  belt,  this  conveyor  is  provided  with  a 
brush  underneath  the  driving  drum  at  the  top  of  the  incline  which 
cleans  the  belt  of  any  material  that  may  remain  attached  to  it. 

The  Robins  belt  conveyor  was  used  by  Messrs.  Ryan  &  Parker 
in  excavating  for  the  foundations  of  the  new  120,000-H.P.  power- 
house of  the  New  York  Gas  and  Electric  Light,  Heat,  and  Power 
Company  at  Thirty-eighth  Street  and  East  River,  New  York.  This 
plant  covers  an  entire  city  block.  The  work  was  done  during 
very  cold  weather,  being  commenced  in  December,  1899,  and 
finished  in  January,  1900.  An  open  trench  7  ft.  deep  was  dug, 
running  through  the  center  of  the  lot.  In  this  the  conveyor  was 
installed.  Across  this  trench  three  bridges  were  laid  with  a  hole 
about  3  ft.  square  in  the  center  of  each,  with  chutes  leading  from 
these  holes  to  the  conveyor.  A  large  number  of  wheel  scrapers 
constantly  passing  over  these  bridges  dumped  their  loads  into 
the  holes.  The  material  fell  onto  the  belt  which  carried  it  away, 
running  level  for  the  greater  part  of  its  length  but  taking  a  verti- 
cal curve  of  about  100  ft.  radius  as  it  approached  the  river  until 


HAULING   EXCAVATED    MATERIALS    ON    INCLINED    ROADS.       185 

a  height  of  20  ft.  was  attained.  At  this  point  it  delivered  the 
material  into  a  large  barge,  which  when  filled  was  towed  out  to 
sea  and  dumped.  The  conveyor  was  driven  at  its  head  end  by 
a  small  horizontal  engine,  very  little  power  being  required.  It 
was  subjected  to  the  roughest  kind  of  usage,  rocks  weighing  over 
100  Ibs.  being  constantly  dumped  upon  it,  but  it  never  caused  a 


FIG.  89a. 

moment's  stoppage  during  the  entire  work.  The  width  of  the 
belt  was  30  ins.  and  the  actual  quantity  of  material  removed 
exceeded  1200  cu.  yds.  per  day.  The  work  was  so  satisfactory 
that  the  contractors  declare  that  they  will  make  use  of  the  Robins 
belt  conveyor  in  any  excavating  which  they  meet  with,  provided 
of  course  that  the  conditions  are  suitable. 


CHAPTER  XIV. 

VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS. 

A  DIFFERENT  method  of  hauling  materials  is  employed  when 
the  horizontal  distance  between  the  cut  and  fill  is  very  small, 
while  the  vertical  distance  is  great,  or  when  a  great  difference  of 
level  must  be  overcome  in  order  to  send  the  excavated  materials 
to  the  fills,  or  spoil-banks.  In  such  a  case  it  is  very  difficult  to 
construct  inclines,  and  it  is  preferable  to  hoist  or  raise  the  mate- 
rials either  directly  or  indirectly  in  a  vertical  direction.  It  is 
termed  direct  hoisting  when  the  buckets  containing  the  materials 
are  attached  directly  to  the  hoist  ing- cable  of  the  machines,  and 
it  is  termed  indirect  hoisting  when  the  cable  is  attached  to  a  plat- 
form or  some  other  device  upon  which  are  placed  the  cars  contain- 
ing the  excavated  materials.  Again,  either  direct  or  indirect 
hoisting  can  be  done  by  machines  which  simply  raise  the  materials 
in  a  vertical  direction;  but  direct  hoisting  can  be  also  done  by 
machines  which  not  only  raise  the  materials  in  a  vertical  direc- 
tion, but  transfer  them  horizontally.  The  principal  hoisting- 
machines  are  the  windlass,  horse-gin,  and  elevators,  while  those 
which  both  hoist  and  transfer  the  materials  are  cranes  and  der- 
ricks. 

Windlass. — The  simplest  and  oldest  hoisting-machine,  is  the 
windlass.  This  consists  of  a  horizontal  wooden  drum  about  2  ft. 
in  diameter,  its  axis  usually  formed  of  an  iron  rod  which  is  pro- 
duced and  bent  so  as  to  form  a  crank  at  each  end  of  the  drum. 
In  some  cases  the  drum  ends  with  one  or  two  large  wheels  fur- 
nished with  iron  handles.  The  drum  is  ordinarily  made  up  of 
three  wooden  circles.  Nailed  around  their  circumferences  there 
are  hard-wood  staves,  which  can  be  either  close  together  or  a  little 

186 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.    187 


apart.  The  drum  is  supported  by  two  vertical  trusses.  Around 
the  drum  is  wound  the  hoist ing-rope,  which  has  its  two  ends  free. 
To  these  ends  are  attached  th^  buckets  containing  the  material. 
The  rope  should  be  longer  than  twice  the  depth  at  which  the 
materials  are  excavated,  because  it  is  wound  three  or  four  times 
around  the  drum.  The  windlass  is  operated  by  two  laborers, 
who  turn  the  cranks  or  the  wheels.  To  obtain  the  greatest  effi- 
ciency from  the  windlass  it  is  necessary  to  have  the  axis  of  the 
drum  a  little  higher  than  half  the  height  of  an  ordinary  man,  so 
that  the  handle  of  the  wheel  in  its  higher  position  will  reach  about 
to  the  shoulder  of  the  operator;  it  is  also  necessary  to  have  at 
the  ends  of  the  rope  two  buckets  of  equal  capacity.  The  windlass 
is  placed  directly  above  the  shaft. 

Windlasses  are  very  seldom  employed  to-day  except  in  cases 
where  a  small  quantity  of  material  is  to  be  removed  from  a  small 
depth,  and  the  work  of  excavation  proceeds  very  slow,  as  is  the 
case  in  the  excavation  of  small  piers.  As  a  rule  it  is  admitted 
that  windlasses  are  suitable  for  hoisting  materials  from  a  depth 
not  greater  than  30  ft.  and  when  the  total  quantity  of  the  mate- 
rial does  not  exceed  300  cu.  yds. 

The  windlass  is  operated  by  two  workmen,  and  -the  cost  of 
hoisting  a  unit  of  volume  of  material  varies  with  the  weight  of 
the  material  and  the  depth  of  the  hoist.  The  cost  of  hoisting 
1  cu.  yd.  of  various  materials  from  different  depths  is  given  in 
the  following  table;  the  prices  are  calculated  on  a  basis  of  $1.50 
per  day  of  ten  hours. 


Materials. 

Depth. 

Common  Loam 

Sand  and  Gravel 

Clay 

Rock 

(76  Lbs.  per 
Cubic  Foot). 

(98  Lbs.  per 
Cubic  Foot). 

(120  Lbs.  per 
Cubic  Foot). 

(170  Lbs.  per 
Cubic  Foot). 

From  10  to 

0.14 

0.18 

0.22 

0.31 

"      20  ' 

0.185 

0.24 

0.29 

0.42 

"      30  ' 

0.28 

0.36 

0.44 

0.62 

"      40  ' 

0.37 

0.48 

0.58 

0.84 

"      50  ' 

0.46 

0.60 

0.90 

1.04 

"    100  ' 

0.80 

1.02 

1.26 

1.80 

188  EARTH  AND  ROCK  EXCAVATION. 

Horse-gin.  —  The  horse-gin  consists  of  a  vertical  shaft  pro- 
vided with  a  drum  at  its  top,  around  which  is  wound  the  hoisting- 
rope.  Two  or  four  arms,  depending  upon  the  number  of  horses 
employed  as  motive  power,  are  connected  to  the  vertical  shaft, 
which  is  called  the  drum  shaft.  The  horses  are  hitched  to  the 
arms.  The  connection  of  the  arms  with  the  drum  is  made  by 
means  of  forks  which  allow  traction  in  opposite  directions.  The 
drum  shaft  ends  with  an  iron  pivot  at  each  extremity,  the  lower 
one  turning  in  a  bell-metal  cup  and  the  upper  one  in  a  collar, 
which  is  usually  in  the  middle  of  a  beam  longer  than  the  arms 
and  fixed  to  the  ground  by  inclined  props.  The  beam  and  in- 
clined props  form  the  structure  which  supports  the  shaft  and 
consequently  the  drum.  The  drum  carrying  the  rope  is  divided 
into  two  parts  by  a  fillet,  thus  separating  the  ascending  from  the 
descending  rope,  and  it  is  furnished  with  horns  projecting  from 
top  and  bottom  so  as  to  prevent  the  rope  from  working  off.  The 
horse-gin  is  not,  like  the  windlass, .  placed  directly  above  but  at 
one  side  of  the  hoisting-place.  The  hoisting-rope  is  wound  around 
the  drum  in  a  horizontal  position,  but  assumes  a  vertical  direction 
inside  the  shaft.  This  is  obtained  by  passing  it  over  a  sheave 
placed  on  a  truss  just  above  the  pit.  The  radius  of  the  drum 
should  be  proportional  to  the  length  of  the  arm,  the  most  favor- 
able ratio  being  1  to  4. 

The  power  of  the  horse-gin  is,  of  course,  much  greater  than 
that  of  a  windlass  operated  by  hand,  buckets  of  1  cu.  yd.  capacity 
being  commonly  used.  According  to  Mr.  Lanino,  who  used 
horse-gins  extensively  in  connection  with  the  construction  of 
several  tunnels  on  the  Napoli  Foggia  Railroad  across  the  Apennines 
Mountains,  horse-gins  are  no  longer  economical  hoisting-machines 
when  y(#>20)>5000,  where  V  equals  the  volume  of  the  mate- 
rial to  be  hoisted  and  H  equals  the  height  of  the  hoist,  the  weight 
of  the  excavated  material  being  2100  Ibs.  per  cu.  yd.  As  a  gen- 
eral rule,  however,  it  is  assumed  that  it  is  not  economical  to 
employ  horse-gins  with  a  depth  of  hoist  exceeding  150  ft.  In 
the  following  tables  are  given  the  cost  of  hoisting  1  cu.  yd.  of 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS,    189 


different  materials  from  various  depths  by  means  of  horse-gins, 
operated  by  one  and  two  horses  respectively: 


HORSE-ffIN    OPERATED    BY   ONE   HORSE. 


Height. 

Common  Loam 
(76  Lbs.  per 
Cubic  Foot). 

Sand  and  Gravel 
(98  Lbs.  per 
Cubic  Foot). 

Clay 
(120  Lbs.  per 
Cubic  Foot). 

Rock 
(170  Lbs.  per 
Cubic  Foot). 

50 

0.14 

0.19 

0.215 

0.32 

100 

0.16 

0.22 

0.27 

0.40 

150 

0.20 

0.245 

0.32 

0.44 

200 

0.22 

0.27 

0.36 

0.49 

300 

0.27 

0.32 

0.42 

0.59 

HORSE-GIN    OPERATED    BY    TWO    HORSES. 


50 

0.113- 

0.146 

0.184 

0.259 

100 

0.135 

0.185 

0.210 

0.315 

150 

0.155 

0.215 

0.265 

0.395 

200 

300 

Elevators. — Where  large  quantities  of  materials  are  to  be 
hoisted  rapidly,  it  is  generally  considered  preferable  to  employ 
elevators  instead  of  hoisting  the  skips  directly.  Besides,  the 
loads  carried  by  elevators  are  much  greater  than  those  carried 
in  a  single  skip  by  other  machines. 

The  elevator  consists  of  a  car  made  up  of  an  open-framework 
box  of  timber  and  iron,  having  a  plank  floor  on  which  car-tracks 
can  be  laid,  and  its  roof  arranged  for  connecting  the  hoisting-cable. 
Rigid  construction  is  necessary  to  resist  the  hoisting  strains.  The 
sides  of  the  car  are  usually  designed  to  slide  against  timber  guides 
or  on  ropes  placed  against  the  shaft  walls.  Some  form  of  safety 
device,  of  which  there  are  several,  is  employed  to  prevent  the  fall 
of  the  elevator,  in  case  the  hoisting-rope  breaks  or  some  mishap 
occurs  to  the  hoisting  machinery  which  endangers  the  fall  of  the 
car.  The  car  is  hoisted  by  means  of  a  wire  hoist  ing- rope  of  usual 
construction  and  dimensions,  and  able  to  safely  resist  the  weight. 
The  hoist  ing- rope,  by  means  of  sheaves  located  at  convenient 
places,  passes  over  and  around  the  drum  of  a  hoisting-engine, 
which  must  be  reversible.  Elevators  may  be  also  moved  by 


190 


EARTH   AND    ROCK    EXCAVATION. 


horses,  and  <this  kind  of  machine  is  constructed  by  the  American 
Hoist  and  Derrick  Company  of  St.  Paul,  Minn.  Fig.  90  illustrates 
the  elevator-car  provided  with  tracks  as  built  by  the  Lidgerwood 
Manufacturing  Company  of  New  York. 

The  plant  required  for  elevators  is  more  extensive  and  costly 
than  the  one  required  for  other  hoisting -machines,  hence  they 

are  employed  only  when  the 
material  is  to  be  hoisted  in 
large  quantities  from  a  great 
depth,  and  when  the  work 
will  extend  over  a  long 
period  of  tune.  This  man- 
ner of  hoisting  is  more  suit- 
able for  mining  and  tunnel- 
ing, and  is  very  seldom 
employed  in  ordinary  earth- 
work excavations,  but  con- 
tractors commonly  employ 
elevators  in  hoisting  mate- 
rials in  the  construction  of 
new  buildings. 

Cranes. — The  crane  is  a 
modern  and  powerful  ma- 
chine, generally  employed 
for  raising  or  lowering  heavy 
weights  or  for  removing 
them  from  one  position  to 
another.  Cranes  are  con- 
FIG.  90.  structed  of  different  shapes, 

but  the  most  common  con- 
sists of  an  upright  revolving  shaft,  with  a  projecting  arm  or  jib,  hav- 
ing a  fixed  pulley  at  the  upper  extremity,  over  which  passes  one  end 
of  the  hoisting-rope  or  chain,  so  as  to  receive  the  weight,  the  other 
end  being  attached  to  a  cylinder  provided  with  wheel  and  pinion, 
by  means  of  which  the  weight  is  raised  to  the  required  height.  By 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.    191 

the  revolving  motion  of  the  upright  portion  the  load  can  be 
deposited  on  any  spot  within 'the  sweep  of  the  jib. 

Cranes  are  built  of  ^different?1  patterns;  some  of  them  have  a 
curved  jib,  while  in  others  the  jib  is  composed  of  a  straight  beam 
which  can  be  either  single  or  built  up  of  different  pieces.  In 
regard  to  the  motive  power  employed,  cranes  can  be  grouped  into 
hand-  and  steam-cranes;  and  both  of  these  can  be  subdivided 
again  into  fixed  and  movable  cranes.  Fixed  cranes  operated 
either  by  hand  or  by  steam  are  usually  employed  on  wharfs,  fac- 
tories, storage-houses,  etc.,  while  movable  steam-cranes  only  are 
employed  by  contractors  in  the  execution  of  public  works.  Cranes 
are  very  commonly  employed  in  England  and  Continental  Europe, 
but  they  do  not  find  great  favor  among  American  engineers  and 
contractors.  Only  two  types  of  cranes  will  be  illustrated  here, 
viz.,  the  crane  derrick  and  the  locomotive  crane,  arid  their  descrip- 
tion is  given  because  they  are  the  only  ones  employed  in  public 
works. 

Crane  Derrick. — The  American  crane  derrick,  distinguished 
from  the  English  steam-crane  derrick,  which  is  a  true  derrick  and 
will  be  described  later  on,  consists  of  a  vertical  mast  provided 
with  steel  bottom  of  usual  construction,  and  resting  on  a  wooden 
block.  The  mast  is  kept  vertical  by  means  of  guys.  At  a  point 
about  two-thirds  of  the  height  of  the  mast  is  the  boom,  which  is 
another  beam  placed  nearly  horizontally,  having  an  inward  incli- 
nation so  as  to  facilitate  the  descending  of  the  weights  along  the 
boom  toward  the  mast.  On  the  upper  side  of  the  boom  there 
are  tracks  made  of  light  rails,  upon  which  rolls  the  trolley  that 
guides  the  trolley-line.  The  trolley  is  moved  toward  the  boom 
end  by  the  trolley-line  running  on  the  engine.  Releasing  the 
pull  on  the  trolley-line  allows  the  load  to  move  down  the  inclina- 
tion of  the  boom  toward  the  mast.  The  engine  has  complete 
control  of  the  load,  raising  it  up  or  down  or  moving  it  anywhere 
the  entire  length  of  the  boom.  The  trolley-  and  hoisting-lines 
both  pass  through  the  casting  and  pivot  at  the  foot,  and  thence  to 
a  double-drum  engine. 

The    crane    derrick   illustrated    in   Fig.  91    is   the    one    built 


192 


EARTH    AND    ROCK    EXCAVATION. 


by  the  American  Hoist  and  Derrick  Company  of  St.  Paul,  Minn., 
and  is  of  5-ton  capacity.  The  length  of  the  mast  varies  from  46  to 
72  ft.,  and  that  of  the  boom  from  35  to  55  ft.  The  height  of 
the  boom  from  the  ground  varies  from  25  to  39  ft. 

The  use  of  the  crane  derrick  is  limited  to  the  construction  of 
walls  of  buildings,  setting  columns,  girders,  etc.,  and  since  the 


FIG.  91. 

boom  is  generally  30  or  40  ft.  from  the  ground  it  handles  all  the 
work  for  two  stories  without  moving.  By  setting  up  the  crane 
derrick  on  a  trestlework  of  any  convenient  height,  any  building 
can  be  entirely  completed  without  removing  the  derrick.  The 
engine  is  usually  located  in  the  cellar  or  ground  floor,  and  commu- 
nication is  obtained  by  means  of  electric  bells. 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.    193 

Locomotive  Crane. — The  other  crane  commonly  employed  in 
earthworks,  especially  in  Europe,  is  the  locomotive  crane  illustrated 
in  Fig.  92.  This  consists  of  a^f our- wheeled  iron  truck  running 
on  tracks.  On  the  truck  is  fixed  a  large  horizontal  cog-wheel 
whose  axis  is  fitted  into  a  socket  of  an  iron  frame,  with  wooden 
platform  upon  which  are  placed  the  boiler  and  the  engine.  In  front 
of  the  iron  frame  there  is  a  boom  or  jib  braced  by  means  of  iron 
rods  connected  to  vertical  iron  stands,  and  tied  to  the  rear  of  the 


FIG.  92. 

iron  frame  of  the  truck  by  diagonal  backstay  rods  provided  with 
turnbuckles.  The  boom  or  jib  is  made  in  different  ways  and  of 
different  materials,  but  usually  it  is  made  of  curved  iron  except  when 
very  long,  then  it  is  made  of  trussed  steel.  One  end  of  the  hoisting- 
chain  is  fixed  to  the  upper  point  of  the  boom;  the  chain  supports 
a  fall-block,  and  after  passing  over  a  sheave  located  on  top  of 
the  boom,  is  wound  around  the  drum  of  the  reversible  engine. 
In  this  manner  the  weight  attached  to  the  fall-block  can  be  lifted 
or  lowered  at  will.  The  engine  is  so  arranged  that  by  putting 
into  gear  another  small  cog-wheel  whose  cogs  engage  those  of  the 
large  one  supporting  the  platform,  the  platform  and  boom  and 


104  EARTH  AND  ROCK  EXCAVATION. 

consequently  the  attached  weight  turn  a  complete  circle.  This 
machine  is  called  a  locomotive  crane  on  account  of  being  provided 
with  a  self-propelling  apparatus.  All  the  motions  of  this  crane, 
viz.,  the  traveling  on  the  rails,  the  lifting  and  lowering  of  the 
loads,  and  the  turning  are  actuated  by  steam  generated  by  the 
boiler  standing  on  the  platform  of  the  truck. 

Locomotive  cranes  are  built  to  run  on  either  standard  or 
broad-gauge  track,  and  their  capacity  varies  from  1  to  35  tons. 
Fig.  93  illustrates  a  5-ton  locomotive  crane  as  built  by  Grafton  & 


FIG.  93. 

Co.,  Engineers,  Vulcan  Works,  Bedford,  England,  while  Fig.  92 
represents  a  3-ton  locomotive  crane  built  by  the  American  Hoist 
and  Derrick  Company.  In  the  locomotive  cranes  of  American 
build  the  boom  is  so  arranged  that  its  upper  point  may  be  raised 
or  lowered  by  turning  the  turnbuckles  in  the  diagonal  backstay 
rods,  and  this  increases  the  utility  of  this  machine. 

The  efficiency  of  the  work  of  these  machines  varies  with  their 
size,  and  an  output  of  1000  cu.  yds.  of  earth  can  be  obtained. 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.    195 

Locomotive  cranes  are  very  advantageously  employed  in  the 
excavation  of  trenches  in  whi'ch  the  materials  are  deposited  either 
on  one  side  of  the  trench  or  at  $riy  point  along  the  line.  A  10-ton 
locomotive  crane  was  successfully  employed  by  Messrs.  Farrell  & 
Hooper,  the  contractors  for  Sections  7  and  8  of  the  New  York 
rapid-transit  railway,  for  the  removal  of  the  excavated  materials 
from  the  bottom  of  the  wide  trench  to  the  surface  of  the  street. 
This  method  of  hoisting  was  employed  in  that  portion  of  the 
work  extending  along  Lenox  Avenue  from  110th  to  116th  streets, 
and  it  was  adopted  because  the  crane  could  be  run  over  the  tracks 
of  a  disused  street-car  line  running  very  close  and  parallel  to  the 
edge  of  the  trench. 

This  locomotive  crane,  described  by  the  writer  in  Engineering 
(Jan.  3,  1902),  was  built  at  the  Industrial  Works  of  Bay  City,  Mich. 
The  car-body  of  the  crane  was  made  of  steel  with  sills  of  15-in. 
I  beams  and  channels  well  connected  together,  and  had  a  decking 
of  steel  plates  to  carry  the  top.  The  crane  was  operated  by  the 
engines  by  means  of  a  train  of  bevel  gearing.  To  the  frame  of 
the  crane  were  secured  the  boxes  of  the  shaft  which  worked  the 
mechanism  for  hoisting  the  load,  slowing  the  crane,  and  varying 
the  jib  radius.  The  boiler  was  42  ins.  in  diameter  and  9  ft.  high, 
and  was  surrounded  with  a  jacket  of  asbestos- wool  and  planished 
iron.  One  side  of  the  boiler  carried  a  coal-bunker  with  drop-door, 
while  the  other  had  a  sheet-steel  water-tank.  The  crane  was 
operated  by  a  double  reversible  engine  with  an  8-in.XlO.-in. 
cylinder.  Flexible  wire  rope  was  used  in  hoisting.  The  capacity 
of  the  crane  varied  with  the  radius  of  the  jib,  being  10  tons  with 
a  12-ft.  radius,  5  tons  with  a  25- ft.  radius;  and  if  a  longer  jib  was 
used,  5000  Ibs.  with  a  38-ft.  radius.  The  total  weight  of  the  crane 
itself  was  66,000  Ibs. 

The  cost  of  working  with  the  locomotive  crane  was  found  by 
Messrs.  Farrell  &  Hooper  to  be  less  than  with  any  other  method 
of  hoisting.  This  economic  advantage  was  due  to  the  existence 
of  the  tracks,  along  which  the  crane  could  easily  travel  and  with- 
out interfering  in  the  least  with  street  traffic. 

Derrick. — A  hoisting-machine  very  commonly  employed   by 


196  EARTH  AND  ROCK  EXCAVATION. 

American  engineers  and  contractors  in  the  execution  of  public 
works  is  the  derrick.  This  can  be  simply  described  as  composed 
of  a  vertical  mast  resting  on  a  foot-block  of  special  construction, 
and  a  long  movable  jib  or  boom  hinged  at  the  bottom  of  the  mast. 
The  top  of  the  boom  is  held  by  a  chain  or  rope  which  passes  over 
sheaves  located  both  at  the  top  and  bottom  of  the  mast,  and  in 
such  a  way  that  the  boom  may  be  raised  or  lowered  at  will. 

Foot-block. — The  foot-block,  which  really  is  the  foot  of  the 
derrick,  is  made  partly  of  timber  and  partly  of  iron.  Two  square 
beams  12X12  ins.  and  5  or  6  ft.  long  are  placed  on  the  ground, 
about  1  ft.  apart.  To  these  timbers  is  bolted  the  base-plate, 
which  is  usually  made  of  cast  or  wrought  iron,  having  on  its  lower 
part  two  vertical  plates  which  support  two  sheaves  called  steps, 
because  they  turn  to  a  right  angle  the  hoisting-  and  boom-lines 
of  the  machine.  On  the  center  of  the  base-plate  there  is  a  hollow 
cylinder  of  great  thickness,  from  8  to  10  ins.  high,  and  strength- 
ened by  diagonal  vertical  plates.  The  cylinder  is  stepped  off 
about  4  ins.  in  height  in  order  to  receive  the  hollow  part  of  the 
mast  and  boom-bottom,  which  perfectly  fit  into  it;  thus  allowing 
the  derrick  to  revolve  on  itself,  the  cylinder  acting  as  a  pivot  of  the 
system.  Fig.  94  represents  the  iron  part  of  the  foot-block  as  built 
by  the  American  Hoist  and  Derrick  Company,  the  timber  being 
omitted  to  better  indicate  the  plate  and  sheaves  which  are  placed 
between  the  timbers.  The  mast-bottom,  as  shown  in  the  figure, 
is  provided  with  an  iron  box  to  receive  the  lower  end  of  the  mast, 
and  it  is  furnished  with  projecting  iron  plates  to  which  are  hinged 
the  other  plates  bolted  to  the  end  of  the  boom. 

Mast  and  Boom. — The  mast  and  boom  are  usually  made  of 
square  yellow  pine-beams  with  a  cross-section  varying  from  8X8 
to  16X16  ins.  The  length  of  both  the  mast  and  boom  varies 
greatly.  The  length  depends  either  on  the  form  of  the  derrick 
or  upon  the  work  expected  from  the  machine;  sometimes  the 
mast  is  longer  than  the  boom,  sometimes  instead  the  boom  is 
twice  as  long  as  the  mast.  Masts  and  booms  made  of  simple 
square  timbers  are  employed  for  lengths  not  greater  than  40  ft. 
For  greater  length,  to  prevent  deflection,  both  the  mast  and  boom 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.    197 

are  stiffened  with  trussed  rods  passing  over  a  crosstree  at  the 
center  of  the  beams,  or  else  they  are  made  of  superior  material,  as 
steel  pipes,  or  latticed"  beams  made  up  of  different  pieces  joined 
together,  which  are  similarly  stiffened  with  trussed  rods  passing 
over  one  or  more  crosstrees.  In  this  manner  derricks  have  been 
built  with  masts  150  ft.  and  booms  135  ft.  long,  respectively. 

Wire    Ropes. — For  derrick  work,  where  sheaves,  blocks,  and 
drums  are  necessarily  of  small  diameters,  it  is  necessary  to  use 


FIG.  94. 

wire  ropes  of  great  flexibility,  thus  avoiding  fracture  of  the  wires 
from  short  bends.  They  are  usually  made  of  six  strands,  nine- 
teen wires  per  strand,  with  hemp  center,  the  wires  being  of 
crucible  or  plow  steel,  the  latter  being  the  stronger  and  also  the 
more  expensive.  The  safe  working  load  of  the  wire  ropes  is 
usually  taken  as  one-fifth  or  one-seventh  of  the  breaking  load.  In 
the  table  on  p.  259  are  given  the  diameter,  weight,  and  breaking 
and  working  loads  of  the  standard  steel  hoisting-ropes  most 
commonly  employed. 

A  derrick  is  able  to  make  three  different  movements  which 


198  EARTH  AND  ROCK  EXCAVATION. 

are  regulated  by  different  ropes:  viz.,  the  hoisting-,  the  boom-, 
and  the  slewing-rope.  The  hoisting-rope  has  one  end  fixed  to 
the  top  of  the  mast,  and  the  other  end  to  one  of  the  drums  of 
the  engine.  From  the  drum  it  goes  around  one  of  the  sheaves 
of  the  foot-block,  and  turning  over  another  sheave  located  near 
the  foot  of  the  mast  goes  to  the  top  of  the  boom,  where  it  passes 
over  another  sheave,  goes  to  support  the  fall-block,  and  its  end  is 
fixed  to  the  top  of  the  boom.  By  revolving  the  hoisting-drum  of 
the  engine,  the  fall-block,  together  with  the  attached  weight,  may 
be  raised  or  lowered  at  will. 

The  second  movement  of  the  derrick  is  to  raise  or  lower  the 
boom,  and  consequently  to  get  it  closer  or  farther  from  the  mast. 
This  is  obtained  by  means  of  a  second  rope  called  the  boom-line, 
which  is  wound  around  another  drum  of  the  engine,  and  passes 
around  the  other  sheave  of  the  foot- block ;  thence  to  the  top  of  the 
mast,  where  it  turns  again  by  passing  over  a  sheave,  and  thence 
to  and  through  a  block  attached  to  the  upper  extreme  of  the 
boom;  and  thence  again  to  the  top  of  the  mast.  By  revolving 
the  second  drum  of  the  engine  commanding  the  boom-line,  the 
upper  end  of  the  boom  may  be  drawn  either  near  to  or  far  from 
the  mast. 

The  third  movement  of  the  derrick,  which  is  to  slew  the  mast 
around  on  its  axis,  and  consequently  also  the  boom  with  the  at- 
tached weight,  is  usually  made  by  hand.  For  this  purpose  another 
rope,  ordinarily  of  manila,  is  tied  to  the  upper  end  of  the  boom,  and 
a  workman  pulls  the  boom  to  the  required  place.  Such  hand  move- 
ment, however,  is  too  slow  and  expensive,  especially  when  a 
weight  of  2  tons  or  more  is  attached  to  the  fall-block,  since  then 
two  or  even  three  workmen  are  required  to  slew  the  boom.  For 
the  sake  of  economy  this  third  movement  is  also  made  by  machine, 
and  then  the  foot  of  the  mast  is  provided  with  what  is  called 
a  bull-wheel.  This  consists  of  a  large  horizontal  wooden  wheel 
furnished  with  a  grooved  rim  to  prevent  the  slewing-line  from 
working  off.  The  wheel  is  strongly  braced  to  the  bottom  of  the 
mast,  and,  as  indicated  in  Fig.  95,  also  to  the  boom  to  relieve 
the  hinges  of  the  boom  from  side  twists.  Two  guiding-sheaves 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS,   199 

are  placed  horizontally  on  the  foot-block  to  direct  the  two  lines 
to  the  sle wing-drum  of  the  engine.  The  engine  in  such  a  case  is 
provided  with  three  churns— ofee  for  the  hoisting-,  a  second  for 
the  boom-,  and  the  third  for  the  slewing-ropes.  By  this  simple 
arrangement  one  man  at  the  engine  can  lift  the  load  and  slew  it 
to  the  desired  place  in  the  same  length  of  time  that  it  takes  to  do 
only  the  lifting  in  derricks  not  furnished  with  bull- wheels.  This 
slewing  device  was  at  first  introduced  in  the  most  powerful  der- 
ricks, as  those  employed  in  the  excavation  of  the  Chicago  Drainage 
Canal,  but  it  is  now  found  in  nearly  every  work  of  importance. 
When  special  three-drum  engines  are  not  at  hand,  the  lines  of 
the  bull- wheel  for  slewing  the  boom  are  commanded  by  the  winch- 
heads  of  the  two  drums,  and  in  such  a  case  the  slewing  of  the 
boom  is  made  after  the  hoisting  has  been  completed,  instead  of 
the  two  movements  being  simultaneous,  as  with  the  three-drum 
engine. 

An  enormous  variety  of  derricks  is  found  on  the  market. 
Nearly  every  manufacturer  has  his  own  particular  way  of  arrang- 
ing the  sheaves,  the  top  of  the  boom  and  mast,  the  foot-block,  etc., 
giving  rise  to  the  claims  of  several  patents,  every  one,  as  usual, 
being  considered  a  great  improvement.  Really  all  derricks  are 
similarly  constructed,  and  differ  only  in  small  details.  For  the 
sake  of  facilitating  the  description  of  these  hoisting-machines,  they 
will  be  divided  into  three  groups:  viz.,  stiff-leg  derrick,  guy  der- 
rick, and  traveling  derricks. 

Stiff-leg  Derrick. — This  derrick,  like  any  other,  consists  of  a 
vertical  mast,  and  a  boom  hinged  to  the  foot  of  the  mast.  It 
rests  on  a  foot-block  which  differs  somewhat  from  the  one  already 
described,  because  instead  of  the  two  short  timbers  placed  parallel 
one  to  another,  the  timbers  in  the  stiff-leg  derrick  meet  at  right 
angles  and  are  very  long;  they  are  called  sills.  The  mast  is  kept 
vertical  by  means  of  two  backstays  abutting,  with  one  end  near 
the  extremities  of  the  sills,  while  at  the  other  end  are  bolted  iron 
plates  furnished  with  a  pinhole.  At  the  top  of  the  mast  there  is 
a  steel  pin  projecting  not  less  than  6  ins.  in  length.  The  pinhole 
of  the  backstays  clasps  the  pin  and  keeps  the  mast  vertical,  and 


200 


EARTH   AND    ROCK   EXCAVATION. 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.   201 

yet  allows  it  to  turn  around  on  its  axis.  The  sills  and  con- 
sequently the  backstays  being*  at  right  angles,  the  boom  can  be 
slewed  three-quarters  of^a  circlet 

Stiff-leg  derricks  are  built  of  any  form,  dimension,  and  capacity. 
Those  most  commonly  employed  in  public  works  have  a  boom 
25  ft.  long,  with  a  capacity  varying  from  2  to  3  tons.  In  this 
kind  of  derrick  the  boom  is  usually  longer  than  the  mast,  and  it 
is  made  of  timber,  iron,  or  steel,  and  sometimes  is  reinforced  by 
truss-rods  passing  over  a  crosstree  at  the  center  of  the  beam. 

Fig.  95  illustrates  a  stiff-leg  derrick  of  ordinary  construction, 
provided  with  a  bull-wheel  for  slewing  the  boom,  as  built  by  the 
American  Hoist  and  Derrick  Company. 

Guy  Derrick. — The  mast  of  the  guy  derrick  rests  on  a  foot- 
block  of  a  similar  construction  to  the  one  described  and  illus- 
trated by  Fig.  94,  and  the  top  is  provided  with  a  steel  gudgeon- 
pin.  The  mast  is  kept  vertical  by  means  of  wire  ropes  or  guys 
spreading  radially  from  the  top.  In  order  to  keep  the  mast  per- 
fectly vertical,  it  is  necessary  that  the  ropes  be  very  tight.  The 
ropes  are  made  fast  to  the  top  of  the  mast  by  means  of  a  guy-cap 
or  gudgeon-plate,  as  it  is  more  commonly  called.  This  consists 
of  a  wrought-iron  circular  plate  provided  with  a  circular  hole  at 
the  center  to  receive  the  gudgeon-pin  of  the  mast,  and  six  or  eight 
small  holes  around  the  edge  and  of  such  dimensions  as  to  allow 
the  passage  of  the  guys.  To  prevent  the  breaking-off  of  the 
wires  of  the  rope  either  from  short  bends  or  rubbing  against  the 
sharp  edges  of  the  iron  guy-cap,  the  holes  are  molded  into  a 
thimble  shape,  as  indicated  in  Fig.  96.  The  other  ends  of  the 


FIG.  96 


guys  are  tied  to  surrounding  trees,  or  else  to  a  short  but  very 
strong  beam,  placed  horizontally  on  the  ground,  called  the  dead 


202  EARTH  AND  ROCK  EXCAVATION. 

man,  and  kept  in  place  by  a  big  pile  of  stones.  With  more  pow- 
erful derricks  the  guys  are  made  light  by  means  of  turnbuckles 
attached  to  them. 

In  the  guy  derricks  the  boom  is  usually  shorter  than  the  mast, 
and  when  the  guys  are  very  long  or  when  they  are  tied  to  elevated 
points,  the  boom  can  be  slewed  through  a  full  circle.  Both  boom 
and  mast  can  be  made  of  square  timbers,  or  built  up  of  iron  beams 
or  steel  pipes;  and  when  of  great  length  they  are  reinforced  with 
truss-rods  and  crosstrees. 

Guy  derricks  are  made  of  any  dimension  and  capacity.  There 
are  derricks  with  150-ft.  mast  and  135-ft.  boom,  having  a  capacity 
of  10  tons,  while  there  are  others  of  much  smaller  dimensions 
but  of  50-ton  capacity.  Since  the  mast  should  be  perfectly 
vertical  it  is  more  difficult  to  set  up  a  guy  than  a  stiff-leg  derrick. 
The  vertically  is  obtained  by  pulling  the  various  guys  to  the 
required  point.  It  takes  time  and  patience  to  set  up  guy  der- 
ricks. In  regard  to  the  cost  of  the  machine  this  varies  with  the 
size  and  capacity.  As  a  rule  it  can  be  assumed  that  derricks  of 
ordinary  dimensions  will  not  cost  more  than  $200  each.  It  takes 
nearly  six  days'  work  to  set  up  a  guy  derrick,  while  only  one-half 
or  even  one-third  of  this  time  is  required  in  setting  up  a  stiff-leg 
derrick. 

Fig.  97  shows  a  hand-power  guy  derrick  of  ordinary  construction. 

Traveling  Derrick. — The  other  kind  of  derrick  which  will  be 
here  illustrated  is  the  traveling  derrick,  represented  in  Fig.  98. 
This  consists  of  a  platform  car  mounted  on  a  four-wheeled  truck 
running  on  tracks.  At  the  front  edges  of  the  car  there  are 
two  vertical  posts  with  a  crosspiece  on  top,  and  this  frame  is 
made  stiff  by  means  of  the  backstays  provided  with  iron  plates 
bolted  at  the  top  of  the  vertical  posts,  and  at  the  rear  end  of  the 
car.  At  the  center  of  the  crosspiece  of  the  frame  there  is  an 
iron  plate  cored  in  the  middle  so  as  to  receive  the  gudgeon-pin  of 
the  mast,  which  stands  on  another  iron  plate  inserted  in  the  plat- 
form of  the  car  and  provided  with  a  hollow  cylinder  into  which 
fits  the  bottom  of  the  mast.  This  is  made  of  iron  with  the  flanges 
supporting  the  axle  of  a  sheave  and  the  hinges  of  the  bottom  of 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.    203 

the  boom.     Underneath  the  platform  of  the  car  there  is  another 


sheave.     Boiler  and  engine  are  located  in  the  rear  of  the  car,  thus 


FIG.  97. 

preventing  the  tipping  of  the  derrick  by  counteracting  the  weight 
attached  to  the  boom.     When  excessive  weights  are  raised  or 


204 


EARTH  AND  ROCK  EXCAVATION. 


lowered,  it  is  necessary  to  insure  the  stability  of  the  apparatus 
by  adding  ballast  on  the  car. 

The  traveling  derrick  as  well  as  other  derricks  is  capable  of 
three  movements  which,  as  has  been  already  seen,  are  made  by 
the  hoisting-,  the  boom-,  and  the  slewing-lines.  The  arrangement 
of  the  hoisting-line  is  similar  to  that  of  the  stiff-leg  or  guy  derricks, 


FIG.  98. 

while  the  arrangement  of  the  boom-line  is  a  little  different.  This 
is  attached  to  a  pulley  fixed  at  the  top  of  the  boom,  and  turning 
around  another  pulley  attached  to  the  top  of  the  mast,  passes 
over  the  first  to  the  top  of  the  boom.  It  returns  again  to  the 
mast,  passing  over  a  sheave  placed  at  its  top,  and  then  assumes  a 
vertical  direction,  turns  on  another  sheave  inserted  above  the 
crosspiece  of  the  frame,  and  goes  to  one  of  the  drums  of  the  engine. 
When  the  slewing  is  done  by  hand,  a  third  line  is  inserted  at  the 
top  of  the  boom;  but  if  it  is  done  by  machine  the  bottom  of  the 
mast  is  provided  with  a  bull-wheel.  . 

The  traveling  derrick,  as  its  name  clearly  indicates,  is  self- 
propelling.  This  is  accomplished  by  using  a  double  cylinder  and 
double-drum  reversible  engine  provided  with  locomotive  attach- 
ment for  the  car-wheels,  which  is  more  economical  than  to  have  a 
special  engine  for  the  propelling  movement  of  the  car. 

In  the  traveling  derrick  the  boom  is  always  longer  than  the 
mast,  and  in  order  to  avoid  the  tipping  of  the  car  or  the  employ- 


VERTICAL  HAULING  OR  HOISTING  OF  EXCAVATED  MATERIALS.    205 

ment  of  excessive  ballast,  it  is  a  good  practice  to  use  booms  not 
longer  than  three  times  the  gauge  of  the  track.  The  gauge  of 
the  track  varies  from  tije  standard  distance  of  4  ft.  8J  ins.  up  to 
20  ft.,  depending  upon  special  conditions  of  the  locality. 

The  traveling  derrick  is  found  particularly  useful  in  the  con- 
struction of  retaining-walls,  in  laying  the  foundations  of  impor- 
tant buildings,  in  erecting  structural  ironworks,  etc.,  and  in  many 
cases  it  may  be  made  to  take  the  place  of  several  stationary  der- 
ricks. It  is  found  very  convenient  in  trench-works,  as,  for  instance, 
in  building  sewers,  laying  water-pipes  and  gas-mains,  etc.  In 
these  cases  a  track  is  laid  on  each  side  of  the  trench  and  the  car 
straddles  the  ditch. 


CHAPTER  XV. 

TRANSPORTING  EXCAVATED  MATERIALS  BY  AERIALWAYS. 

IN  working  through  rough  and  broken  country  intersected 
by  ravines  or  streams,  or  through  city  streets  where  roads  are 
too  expensive  to  construct  or  are  undesirable  for  other  reasons, 
the  transportation  of  excavated  materials  may  be  very  conve- 
niently accomplished  by  means  of  aerialways.  From  time  im- 
memorial aerialways  in  primitive  forms  have  been  used  for  con- 
veying different  materials  from  one  point  to  another  by  means 
of  a  rope  stretched  between  two  points.  The  writer,  however, 
was  surprised  to  see  in  a  book  written  by  Dr.  Hook,  and  pub- 
lished in  London  in  the  year  1692,  a  contrivance  described  and 
illustrated  which  Sir  Robert  Southwell  saw  used  at  Brandenburg 
for  the  speedy  conveyance  of  earth  to  fill  up  or  raise  ground, 
etc.  It  was  really  a  perfect  aerialway,  and  even  more  compli- 
cated than  many  of  the  contrivances  recently  patented.  It  is 
only  in  the  last  few  years,  however,  that  aerialways  have  found 
extensive  employment  in  the  transportation  of  materials  for 
mining,  industrial,  and  public  works. 

For  the  sake  of  convenience,  under  the  general  name  of  aerial- 
ways  there  are  included  here  all  the  methods  of  conveying  excavated 
materials  in  such  a  manner  that  the  cars,  skips,  buckets,  scales, 
etc.,  instead  of  running  on  tracks  laid  on  the  ground,  are  by  some 
means  suspended  and  moved  on  beams  or  ropes  suspended  in 
the  air.  According  to  this  definition  and  in  order  to  review  in  order 
the  various  means  of  conveyance,  these  aerialways  are  divided  into 
true  aerialways  and  telphers.  In  the  first  group  are  included  all 
aerialways  in  which  the  cars  or  skips  containing  the  material 
.are  moved  by  means  of  ropes  commanded  by  engines;  telphers 

206 


TRANSPORTING  EXCAVATED  MATERIALS  BY  AERIALWAYS.      207 


are  aerialways  in  which  the  cars  are  self  -moving  on  the  suspended 
track,  being  provided  with  '  electric  motors.  In  regard  to  the 
nature  of  the  trackway  true  aerialways  can  be  divided  into  two 
groups:  viz.,  transporters  and  cableways.  They  are  called  trans- 
porters when  the  trackway  is  formed  by  rigid  beams,  and  cable- 
ways  when  it  is  made  of  rope.  Again,  both  transporters  and 
cableways  can  be  subdivided,  according  to  the  manner  of  working, 
into  simple  transportation-lines,  when  several  cars  or  skips  run 
at  the  same  time  on  the  trackway,  and  all  remain  at  the  same 
fixed  distance  from  the  track;  and  into  hoisting-  and  convey  ing- 
machines  when  only  one  car  or  skip  of  large  capacity  runs  on  the 
trackway,  thus  acting  as  a  means  of  conveyance,  and  is  by  some 
device  raised  or  lowered  so  as  to  act  also  as  a  hoisting-machine. 


Aerialways. 


Cars  moved  by  ropes 
commanded  by  en- 
gines. 


rigid  beams. 


Transporters. 


Cars  provided  with  electric  motors  and  self-  j  Telphera  e 


propelling. 


TRANSPORTERS. 


According  to  the  definition  given  above,  aerialways  in  which 
the  track  is  composed  of  rigid  beams  are  called  transporters. 
They  can  be  used  either  as  a  simple  means  of  transportation  or 
as  hoisting-  and  convey  ing-machines. 

The  writer  does  not  know  of  any  transporter  used  exclusively 
as  a  means  of  transferring  materials  from  one  point  to  another, 
with  the  exception  of  the  coal-handling  devices,  which,  up  to  a 
certain  limit,  can  be  considered  as  true  aerialways.  In  fact,  they 
consist  as  a  rule  of  a  double  endless  chain,  to  which  the  buckets 
are  attached  and  guided  on  tracks  made  up  of  rigid  beams.  These 
transporters,  although  convenient  for  factories  or  piers,  have,  to 
the  knowledge  of  the  writer,  never  been  employed  in  public  works 
or  in  mining.  The  reason  they  are  not  used  is  on  account  of  being 
far  more  expensive  than  cableways  of  the  same  capacity,  because 
the  trackway,  being  composed  of  rigid  beams,  has  to  be  supported 


208  EARTH  AND  ROCK  EXCAVATION. 

every  few  feet,  while  cableways  can  be  constructed  with  spans 
running  up  to  thousands  of  feet. 

It  is  a  very  easy  matter,  however,  to  imagine  how  a  trans- 
porter used  exclusively  for  transferring  materials  from  one  point 
to  another  should  be  arranged.  The  trackway  could  be  made  up 
of  two  parallel  lines,  one  for  the  cars  loaded  with  material,  and 
the  second  for  the  empty  cars  traveling  in  an  opposite  direction. 
A  loop  at  each  end  of  the  tracks  will  join  them  and  make  them 
continuous.  The  tracks  should  be  suspended  in  some  way,  either 
to  the  roof  of  the  factory,  shed,  or  pier;  or  else  held  up  above 
the  ground-surface  by  means  of  trestle-bents.  On  the  tracks  may 
travel  the  buckets  carrying  the  materials,  and  they  can  be  in 
such  numbers  as  to  be  only  a  small  distance  apart.  The  move- 
ment of  the  buckets  may  be  effected  by  means  of  an  endless 
hauling-rope  turning  around  two  grooved  horizontal  sheaves  of 
great  diameter  located  just  below  the  loops  at  the  ends  of  the 
tracks.  The  movement  of  the  hauling-rope  is  caused  by  revolving 
one  of  the  sheaves,  and  can  be  regulated  by  the  rapidity  of  revo- 
lution of  the  shaft.  The  buckets  could  be  of  the  same  shape  and 
design  as  those  used  with  the  Otto,  Bleickert,  and  similar  cable- 
ways,  provided  with  a  small  truck  for  running  on  the  tracks  and  a 
grip  for  connection  to  the  hauling-rope.  If  the  line  were  pro- 
vided with  an  automatic  loading  device  and  an  arrangement  for 
dumping  the  buckets,  the  transporter  thus  constructed  would 
certainly  give  perfect  satisfaction  in  regard  to  operation,  but  not, 
perhaps,  in  cost,  which  would  be  higher  than  for  a  cableway. 

Transporters,  however,  are  used  as  hoisting-  and  conveying- 
machines,  and  they  not  only  transfer  the  materials  from  one  point 
to  another,  but  they  lower  and  raise  the  bucket  or  weight  between 
the  tracks  and  the  floor.  These  kinds  of  transportaters  are  pro- 
vided with  only  one  track,  upon  which  the  single  bucket  travels 
back  and  forth  by  means  of  an  endless  rope,  and  is  raised  or  low- 
ered by  means  of  a  second  rope.  Both  ropes  are  commanded  by 
a  drum  on  a  double-drum  reversible  engine. 

Lidgerwood  Transfer. — Of  the  hoisting  and  conveying  trans- 
porters, the  simplest  one  is  the  Lidgerwood  transfer.  This  is 


TRANSPORTING  EXCAVATED  MATERIALS  BY  AERIALWAYS.      209 

provided  with  a  double-track  line  for  the  four-wheeled  truck,  to 
which  is  suspended  the  bucket  containing  the  material  to  be 
transported.  > 

The  trackway  is  composed  of  two  rails  which  can  be  built  in 
different  manners;'  they  can  be  made  of  two  wooden  beams  pro- 
vided with  angle-iron  at  the  edges,  as  at  A ,  Fig.  99 ;  or  of  two  small, 


FIG.  99. 

very  light  rails  placed  upon  longitudinal  wooden  beams,  as  at  5; 
or  they  can  be  made  of  two  channel-irons  upon  which  the  wheels 
of  the  truck  may  run  either  above  the  upper  flange,  as  at  C,  or  on 
the  lower  flanges  and  within  the  channels,  as  at  D.  In  any  case 
the  trackway  is  suspended  from  the  ceiling  or  roof  by  means  of 
hangers,  but  it  could  also  be  easily  supported  by  iron  or  wooden 
bents. 

The  carriage  of  the  Lidgerwood  transfer  consists  of  a  truck 
resting  on  four  small  flanged  wheels.  The  truck  supports  two 
sheaves  around  which  the  fall-block  rope  carrying  the  suspended 
load  is  wound.  The  body  of  the  carriage  varies  in  form,  accord- 
ing to  the  material  to  be  carried.  The  carriage  is  moved  along 
the  trackway  by  means  of  an  endless  carrying-rope,  whose  return 
is  supported  by  sheaves  placed  between  the  hangers  of  the  track- 
way. The  hoisting-rope  is  supported  by  special  carriers  placed 


210  EARTH  AND  ROCK  EXCAVATION. 


below  the  tracks.  These  carriers  are  composed  of  two  distinct 
parts  held  close  together  by  means  of  springs;  one  of  these  parts 
is  provided  with  a  sheave.  The  carriage  is  furnished  with  a 
deflector  which  pulls  apart  the  carrier,  and  when  the  carriage  is 
well  past,  the  carrier  will  resume  its  former  position  and  the  hoist- 
ing-rope will  then  be  supported  again  by  the  carrier.  The 
hoisting-rope  carriers  are  placed  at  a  distance  of  about  50  ft. 
apart. 

The  Lidgerwood  transfer  (Fig.  100)  is  operated  by  a  double- 


FIG.  100. 

drum  reversible  engine,  one  of  the  drums  commanding  the  carrying- 
rope,  while  the  other  drum  regulates  the  hoisting-rope. 

Loads  of  more  than  two  tons  can  be  easily  handled  by  this 
transporter,  which  is  found  very  convenient  for  conveying  mate- 
rials in  warehouses,  coal-sheds,  and  coal-houses,  but  not  in  public 
works.  It  has  been  described  on  account  of  its  simplicity,  and 
because  many  machines  usually  employed  in  the  excavation  of 
trenches  for  sewers,  water-works,  and  other  purposes  are  built  on 
the  same  principle. 


TRANSPORTING  EXCAVATED  MATERIALS  BY  AERIALWAYS.      211 

Moore  Trenching-machine.  —  The  trenching-machines,  which 
are  now  so  commonly  employed  by  contractors  in  public  works, 
are  simply  hoisting  *and  conveying  devices  running  upon  rigid 
trackways.  Fig.  101  illustrates  the  Moore  trenching-machine  built 
by  the  Moore  Manufacturing  Company  of  Syracuse,  N.  Y.  This 
consists  of  a  trackway  composed  of  two  light  steel  rails,  elevated 


FIG.  101. 

not  less  than  10  ft.  above  the  ground,  and  supported  by  a  series  of 
steel  or  iron  bents  braced  together  so  as  to  form  a  solid  structure. 
The  feet  of  the  bents  are  provided  with  small  flanged  wheels,  in 
order  that  they  may  be  easily  moved  along  other  tracks  laid  on 
the  ground,  and  on  both  edges  of  the  excavated  trench. 

On  the  upper  track  moves  the  conveying-car,  made  up  of  a 


212  EARTH  AND  ROCK  EXCAVATION. 

four-wheeled  truck  provided  with  a  platform  having  an  open 
space  in  the  center;  on  this  platform  stands  the  operator.  The 
front  and  back  of  the  truck  is  connected  with  an  endless  rope 
wound  around  the  drum  of  a  reversible  engine,  thus  allowing  the 
truck  to  go  back  and  forth  along  the  upper  tracks.  The  return 
of  the  endless  carrying-rope  is  provided  for  by  means  of  sheaves 
located  at  the  head-  and  tail-tower  of  the  system,  and  supported 
also  by  sheaves  mounted  high  on  the  conveying-car.  Either 
higher  or  lower  than  the  sheaves  supporting  the  returning  carrying- 
rope,  there  are  two  more  sheaves  for  the  support  and  direction  of 
the  hoisting-rope,  which,  through  the  opening  in  the  center  of 
the  platform,  may  reach  the  bottom  of  the  trench. 

The  machine  is  operated  by  a  double-drum  reversible  hoisting- 
engine,  one  drum  commanding  the  endless  carrying-rope,  and 
consequently  the  movement  of  the  conveying-car  along  the  track- 
way; the  other  drum  regulating  the  hoisting-rope.  The  fall- 
block  suspended  to  the  hoisting-rope  carries  the  bucket,  which 
may  descend  to  the  bottom  of  the  trench  or  be  raised  to  a  height 
just  below  the  trackway  of  the  conveying-car.  When  the  bucket 
is  in  this  position,  the  drum  of  the  carrying-rope  is  put  into  gear 
and  the  bucket  moved  along  the  trackway  or  stopped  at  any 
desired  point,  where  the  bucket  discharges  its  contents  either  into 
a  car  so  as  to  be  hauled  away,  or  into  the  rear  portion  of  the 
trench,  where  the  required  work  has  already  been  completed. 

At  the  front  end  of  the  apparatus  there  is  a  platform  car  upon 
which  are  mounted  the  engine  and  boiler  as  well  as  the  head- 
tower,  the  tail-tower  being  similarly  mounted  on  another  platform 
car  at  the  rear  end  of  the  machine.  Both  the  towers  and  the 
bents  being  mounted  on  wheels,  the  machine  may  be  easily  ad- 
vanced, thus  following  the  progress  of  the  work.  The  time 
required  for  advancing  the  machine  can  be  assumed  at  60  ft.  in 
five  minutes. 

The  theoretical  capacity  of  the  machine  is  one  bucket  a  min- 
ute; the  capacity  of  the  bucket  being  a  cubic  yard,  the  work  of 
the  machine  will  be  60  cu.  yds.  per  hour.  In  practical  works, 
however,  such  a  result  is  never  obtained,  because  the  work  inside 


TRANSPORTING  EXCAVATED  MATERIALS  BY  AERIALWAYS.      213 

the  trenches  proceeds  very  slowly  on  account  of  the  narrow  space 
in  which  the  men  work,  and  also  on  account  of  the  strutting  and  the 
construction  of  the  work,  for  which  purpose  the  trench  was  opened. 
The  Moore,  as  well  as  other  similar  machines  found  on  the 
market,  are  extensively  employed  to-day  on  public  works,  be- 
cause they  greatly  reduce  the  expense  of  construction.  One  of 
the  great  advantages  is  that  they  remove  the  necessity  of  piling 


FIG.  102. 

dirt  in  the  public  streets  and  blockading  the  traffic,  especially  in 
narrow  streets.  With  these  machines  the  earth  excavated  at 
the  head  of  the  line  is  conveyed  toward  the  rear  and  employed 
in  backfilling  the  trench  after  the  construction  is  completed. 
The  surplus  of  excavated  materials  is  directly  loaded  from  the 
buckets  into  wagons,  which  may  go  under  the  trackway,  as  indi- 
cated in  Fig.  102.  With  these  machines  the  work  proceeds  with 
the  greatest  regularity,  efficiency,  and  economy. 


214  EARTH  AND  ROCK  EXCAVATION. 

The  Brown  Hoisting-  and  Conveying-machines.  —  Another 
transporter  which  gave  magnificent  results  in  the  excavation  of 
the  Chicago  Drainage  Canal  is  the  Brown  hoisting-  and  conveying- 
machine,  built  by  the  Brown  Hoisting  and  Conveying  Machine 
Company  of  Cleveland,  Ohio.  The  machine,  illustrated  in  Fig-  103, 
was  built  to  answer  all  the  requirements  of  the  work,  which  were 
to  have  a  traveling  conveyor  arranged  in  such  a  way  that  the 
material  excavated  from  the  bottom  of  the  proposed  canal  could 
be  raised  and  deposited  to  a  much  higher  point  on  the  spoil-banks 
located  alongside  and  at  some  distance  from  the  shore.  The 
trackway  was  made  of  an  inclined  cantilever  supported  by  a 
central  tower.  The  following  description  of  the  machine  is  taken 
from  Engineering  of  London. 

The  Brown  hoisting-  and  conveying-machine  is  carried  on 
four  tracks  of  standard  gauge  by  four  trucks  of  four  wheels;  the 
distance  apart  of  the  tracks  between  centers  is  37  ft.  The  tower, 
which  is  mounted  on  a  platform  carried  by  the  trucks,  is  a  strongly 
framed  structure.  It  consists  of  two  pairs  of  columns  braced 
together;  the  front  pair  of  columns  is  53  ft.  in  height  and  the 
back  pair  60  ft.  8  in.  This  difference  in  height  corresponds  to  the 
necessary  inclination  of  the  cantilever,  which  is  set  at  an  angle  of 
12°  50'.  Upon  the  platform,  between  the  columns,  is  placed 
the  power  station,  from  which  all  the  required  manoeuvres  of  the 
cables,  etc.,  are  operated  and  the  power  required  for  propelling 
the  derrick  derived.  The  total  length  of  the  cantilever  is  355  ft., 
which  allows  an  overhang  of  about  150  ft.  into  the  canal-bed, 
while  the  farthest  point  for  dumping  is  nearly  200  ft.  from  the 
edge  of  the  canal.  The  length  of  travel  of  the  buckets  is,  how- 
ever, only  353  ft.  The  height  of  the  lower  end  of  the  cantilever 
above  the  bed  of  the  canal  is  53  ft.,  and  that  of  the  upper  end  is 
93  ft.  above  the  natural  surface.  The  buckets,  holding  about 
1J  yds.,  are  attached  to  the  end  of  the  hoisting-cable  and  raised 
to  the  under  side  of  the  cantilever,  when  a  second  and  hauling- 
cable  transfers  them  for  the  whole  length  of  the  cantilever  or  to 
such  a  point  as  may  be  desired  for  dumping.  This  work  is  per- 
formed in  the  engine-house  on  the  tower,  where  three  different 


TRANSPORTING  EXCAVATED  MATERIALS  BY  AERI ALWAYS.        215 


216  EARTH  AND  ROCK  EXCAVATION. 

motions  are  used  and  controlled  by  three  levers.  One  lever  hoists 
the  bucket  from  pit  to  truss,  another  transfers  it  to  the  other 
cable  and  raises  it  along  the  truss  till,  striking  the  trip,  it  auto- 
matically dumps  and  then  returns  to  the  pit,  and  a  third  lever 
moves  the  whole  derrick  along  the  track. 

The  average  speed  of  the  cantilever  along  the  track  is  about 
150  ft.  per  minute,  but  as  much  as  400  ft.  per  minute  has  been 
made.  The  total  weight  of  truss,  tower,  and  120-H.P.  10J-in.X 
12-in.  engine  is  about  150  tons.  The  buckets  used  are  of  iron 
and  steel  and  contain  75  cu.  ft.  water  measure.  The  records  of 
different  cantilevers  for  long  periods  of  time  show  the  actual 
working  load  to  be  from  1.5  to  1.7  cu.  yds.  in  place  measurement. 
The  greatest  practical  work  of  this  machine  was  obtained  by  two 
of  these  cantilevers  working  in  Section  11,  which  carried  627 
cu.  yds.  per  day  in  a  total  of  forty-nine  days  worked.  Nine 
buckets  are  usually  required  for  the  regular  service  of  these  canti- 
levers and  a  gang  of  five  men  was  employed  for  each  bucket  hi 
the  canal-bottom.  The  cost  of  working  the  Brown  conveyor  is  given 
as  3.58  cents  per  cu.  yd.,  including  all  the  wages,  coal,  stores,  and  re- 
pairs connected  with  the  running  and  maintenance  of  the  machine. 

Temperly  Transporter. — Before  closing  this  review  of  aerial- 
ways  running  upon  rigid  tracks  it  is  necessary  to  mention  the 
Temperly  transporter,  which  is  one  of  the  simplest  and  which 
is  extensively  employed  for  different  purposes.  The  Temperly 
transporter  is  a  hoisting-  and  conveying-machine  employing  a 
suspended  beam  as  a  trackway.  The  special  feature  of  this  trans- 
porter is  the  automatic  carriage  of  novel  design  provided  with 
a  simple  automatic  device  by  which  the  carriage  can  be  held 
stationary  at  various  points  along  its  track  while  the  load  is  being 
lifted  or  lowered,  and  which  sustains  the  load  while  the  carriage 
is  moving.  The  various  movements  of  the  carriage  mechanism 
are  interlocking.  For  example,  the  carriage  is  not  released  from 
holding  to  the  beam  until  the  load  is  released  from  the  carriage, 
and,  vice  versa,  the  load  is  not  released  from  the  carriage  until 
the  carriage  is  firmly  locked  to  the  beam.  Fig.  104  shows  the 
interlocking  mechanism. 


TRANSPORTING  EXCAVATED  MATERIALS  BY  AERIALWAYS.      217 

The  trackway  is  generally  .made  of  a  single  iron  I  beam,  and 
the  carriage  travels  upon  th£  lower  flange  with  two  wheels,  one  on 
each  side  of  the  web.  -  The  befthi  is  generally  suspended  by  means 
of  guys  and  can  be  entirely  suspended,  or  one  end  may  abut 
against  a  mast  or  some  other  firm  support.  It  may  work  at  any 


FIG.   104a. 

angle  and  the  higher  end  may  be  either  inward  or  outward.  When 
the  beam  is  fixed  as  in  factories,  warehouses,  etc.,  it  can  be  made 
of  any  length,  but  the  portable  beam  is  generally  from  30  to  60  ft. 
long.  To  reach  out  long  distances  a  tubular  boom  is  preferable 
to  the  I  beam,  and  in  such  a  case  the  carriage  travels  on  a  track 
suspended  on  the  lower  side  of  the  boom.  In  order  to  stop  the 


218  EARTH  AND  ROCK  EXCAVATION. 

carriage  at  different  points  the  bottom  of  the  lower  flange  of 
the  I  beam  is  provided  with  stops  at  intervals,  in  accordance  with 
the  requirements  of  the  case,  usually  5  ft.  apart.  At  any  of  these 
points  the  carriage  can  be  arrested  at  the  will  of  the  operator 
and  the  load  lowered  or  hoisted.  The  stops  on  the  beam  and 


FIG.  1046. 


the  manner   in  which  the  carriage   is   stopped  are   clearly  indi- 
cated in  Figs.  104a  and  104&. 

The  operations  of  lifting,  transporting,  and  lowering  the  load 
are  effected  by  the  simple  action  of  hauling  in  and  paying  out  a 
single  rope,  and  any  form  of  a  single-drum  hoisting-engine  may 
be  used  for  working  the  transporter. 


TRANSPORTING  EXCAVATED  MATERIALS  BY  AERI ALWAYS.      219 

The  great  success  achievecl  by  the  Temperly  transporter, 
which  in  the  last  few  years  has  been  adopted  by  all  the  maritime 
powers  of  the  world  for  coaling  vessels,  should  attract  the  atten- 
tion of  engineers  and  contractors  to  the  fact  that  it  affords  one  of 
the  simplest  and  most  economical  means  of  hoisting  and  convey- 
ing. The  Temperly  transporter  is  built  to  carry  loads  from  1000 
to  3000  Ibs.,  it  is  easily  set  up  and  removed,  since  its  weight,  the 
carriage  being  included,  does  not  exceed  1  ton.  It  is  handled  by 
one  man  at  the  engine,  and  the  work  of  the  machine  is  from  40 
to  60  tons  per  hour. 


CHAPTER  XVI. 

TRANSPORTING  EXCAVATED  MATERIALS  BY  CABLEWAYS. 

CABLEWAYS  are  aerialways  in  which  the  carrier  is  suspended 
to  a  rope  either  traveling  with  it  or  simply  moving  along  it. 
Within  the  last  thirty  years  this  simple  and  economical  means 
of  transportation  has  found  numerous  .applications,  and  it  is  now 
extensively  used  in  mining  as  well  as  in  public  works.  A  large 
variety  of  cableways  is  found  on  the  market,  and  since  the  manu- 
facturers insist  on  introducing  them  under  the  name  of  the  various 
inventors  there  is.  great  confusion. 

According  to  Mr.  J.  Pearce  Roce,  cableways  can  be  broadly 
.divided  into  two  types.  First,  that  in  wrhich  a  plain  endless  rope 
both  suspends  the  loads  and  moves  them,  and  second,  that  in 
which  the  loads  are  suspended  from  runners  drawn  along  fixed 
cables  by  means  of  a  separate  traction  rope.  Cableways  of  the 
first  type  can  be  divided  again  into  two  groups:  one  in  which  the 
carriers  hang  from  the  rope  and  move  with  it  through  frictional 
contact,  and  another  in  which  the  carriers  hang  from  the  rope 
and  move  with  it,  being  rigidly  fixed  in  position  on  the  rope. 
This  is  the  principle  of  the  Hodgson  and  Hallidie  systems.  The 
cableways  of  the  second  type,  in  which  the  carriers  are  suspended 
to  a  fixed  rope  and  are  hauled  by  a  traction  rope,  can  be  divided 
also  into  two  other  groups,  as,  for  instance,  into  cableways  in 
which  there  is  only  one  rope  used  as  trackway,  or  into  cableways 
in  which  the  trackway  is  formed  by  two  parallel  ropes.  When 
there  is  only  one  rope,  there  is  also  only  one  carrier,  which  is 
drawn  to  and  fro  by  means  of  an  endless  hauling-rope.  All  the 
numerous  hoisting-  and  conveying-machines  which  in  the  last 
few  years  have  been  extensively  used  in  public  works,  as,  for 
instance,  the  Carson  trenching-machine,  the  Locke  &  Miller,  the 

220 


TRANSPORTING    EXCAVATED    MATERIALS    BY    CABLEWAYS.     221 

Flory,  and  other  cableways, .  belong  to  this  group.  Cableways 
may  be  also. made  up  of  t\v*o  fixed  parallel  ropes  with  an  endless 
hauling-rope,  so  that  the  carriers  travel  in  one  direction  and 
return  in  the  other.  The  Otto,  Bleickert,  Leschen,  and  similar 
aerialways  are  constructed  on  this  principle. 

All  the  methods  of  transportation  indicated  above  are  used 
for  hauling  materials  on  horizontal  or  nearly  horizontal  track- 
ways, but  in  many  cases  the  difference  of  level  between  the  ex- 
treme stations  of  the  cableways  is  great,  and  then  the  cableways 
used  are  known  as  inclined  cableways.  These,  however,  can  be 
made  of  one  fixed  rope  on  which  the  carriers  uncontrolled  by 
hauling-ropes  are  allowed  to  run  down  at  a  high  speed,  or  else 
only  one  carrier  is  used,  and  this  is  controlled  by  the  hauling-rope. 
To  the  former  class  belong  the  apparatus  called  "  shoots,"  'and 
to  the  last  inclined  cableways  proper. 

For  sake  of  simplicity  cableways  will  be  reviewed  here  grouped 
in  the  manner  indicated  in  the  following  table.  The  limits  of 
this  book  do  not  allow  a  long  discussion  of  this  subject,  but  further 
information  can  be  obtained  from  the  catalogues  of  the  sev- 
eral manufacturers,  especially  that  of  Bullivant  &  Co.,  Ltd.,  of 
London,  who  employ  and  manufacture  the  various  ropeways 
designed  by  Mr.  W.  Carrington,  M.Inst.C.E.,  one  of  the  pioneers 
and  perhaps  the  most  competent  engineer  in  this  line  of  work  in 
the  world. 

Carriers    hanging    from    a  )   />!__•„       ,a 
rope,    moving     through  I  Ca™f  *on  8 


f  Carriers      hang-  |       frictional  contact.              j 

system  . 

ing  to  an  end-   I 

f  On  horizontal  or  near 

less    running-  ' 
rope. 

Carriers    hanging    from    a  ] 
rope  and  moving  with  it,  ! 
being    rigidly    fixed    in  [ 
position  on  the  rope.         J 

Hallidie's  and 
Hodgson'  s  sys- 
tems. 

horizontal     track-  •< 

iys: 
1  by  ropes. 

ways. 

Carriers  moving 
along       fixed 

'  Only  one  carrier  hanging  j 
from  a  fixed   rope  and  ! 
moved     by    a    hauling-  [ 
rope.                                     j 

Carson  trench- 
ing- machine, 
Locke  &  Miller, 
Flory's,  Roeb- 
ling's,  etc. 

il  • 

ropes. 

Carriers    running    on    two  ^ 

IS 

parallel  ropes  and  moved  1 
along   by   means    of   an  f 

Otto's,  Bleick- 
ert's,  Lescher's. 

o3  M 

o  2 

I.      endless  hauling-rope.        J 

(  Many  carriers  uncontrolled  ) 

One  fixed  rope.    4       by  rope,  descending  by  >•  "Shoots." 
On    inclined    track-  j  (       means  of  gravity. 

[  j  One  carrier  controlled  by  a  {  Inclined     cable- 
1       hauling-rope.  f       way. 


222  EARTH  AND  ROCK  EXCAVATION. 

Carrington  System. — This  system  in  which  the  endless  running- 
rope  has  carriers  hanging  therefrom  and  moving  with  it  through 
frictional  contact  is  described  by  the  inventor,  Mr.  W.  Carring- 
ton, in  the  following  way: 

"  This  system  is  provided  with  a  driving-gear  at  one  end  fitted 
with  a  driving-drum,  varying  from  5  to  10  ft.  in  diameter  and 
arranged  with  suitable  gearing  for  receiving  the  power-steam, 
water,  or  even  horse-power  in  the  case  of  smaller  lines.  At  the 
opposite  terminal  a  similar  wheel  is  placed  and  provided  with 
tightening-gear.  Round  these  two  wheels  an  endless  band  of 
wire  rope  is  placed.  Intermediately  between  them  the  wire  rope 
is  carried  on  suitable  pulleys  of  diameter,  varying  according  to 
the  size  of  the  rope,  the  former  being  carried  on  posts  of  iron  or 
timber,  spaced  about  200  ft.  apart,  and  of  suitable  height  to  enable 
the  carriers  to  clear  intervening  obstacles,  and  also  to  regulate,  to 
a  certain  extent,  the  general  level  of  the  line.  The  carriers  hang 
from  the  rope  and  are  enabled  to  pass  the  supporting  pulleys  by 
means  of  a  curved  hanger,  which,  pivoting  in  the  V-shaped  saddle 
which  rests  on  the  rope,  attaches  at  the  lower  end  to  the  recep- 
tacle by  means  of  a  hook.  The  saddle,  in  an  iron  frame,  is  fitted 
with  wood  or  rubber,  or  composition  friction  blocks,  by  means  of 
which  the  necessary  friction  on  the  rope  is  obtained,  which  enables 
the  carrier  to  pass  with  the  rope  up  steep  inclines  and  over  pulleys/' 

The  frame  which  carries  these  friction  pieces  is  fitted  with 
two  small  wheels  carried  on  pins  attached  to  it,  which  are  called 
shunt  wheels,  and  are  employed  for  removing  the  carrier  from 
the  rope  at  the  terminals  and  at  curves  where  shunt-rails  are 
placed.  These  rails  are  held  in  such  a  position  that  when  the 
carrier  approaches  the  terminal,  the  small  wheels  engage  on  it, 
and  running  up  a  slight  incline,  lift  the  friction  or  clip-saddle  from 
the  rope  and  enable  it  to  pass  to  where  the  loading  and  unloading 
is  required  to  be  done,  or  round  the  curve  wheels.  The  impetus 
derived  from  the  speed  of  the  rope  (about  four  miles  per  hour)  is 
sufficient  to  enable  the  carrier  to  clear  itself  automatically  from 
the  rope  without  difficulty. 

This  method  of  cableways  is  used  for  industrial  purposes,  but 


TRANSPORTING    EXCAVATED   MATERIALS   BY   CABLEWAYS.     223 

not  in  ordinary  excavation  works;  it  is  advantageously  employed 
where  the  quantity  to  be  carried  does  not  exceed  1  in  3;  where 
the  individual  loads  do  not  ^exceed  6  cwt.;  and  also  where  the 
section  of  the  grouncl  does  not  necessitate  spans  of  greater  length 
than  600  ft.  Longer  spans,  steeper  inclines,  greater  quantities, 
and  heavier  loads  can  be  carried  by  this  system,  but  not  so  advan- 
tageously as  by  another  system  referred  to  hereafter. 

Hodgson  and  Hallidie  System.  —  The  Hodgson's  system  takes 
the  name  from  its  inventor,  Mr.  Charles  Hodgson,  who  in  the 
year  1868  secured  a  patent  for  this  means  of  transportation. 
This  has  the  driving-gear,  the  tightening-gear,  the  endless  rope, 
and  the  pulleys,  as  in  the  method  described  above;  the  only  dif- 
ference being  that  the  carriers  are  rigidly  fixed  in  position  on  the 
endless  running-rope,  and  consequently  they  must  go  where  the 
rope  goes.  Such  an  arrangement  allows  steep  inclines  to  be  sur- 
mounted, and  a  great  advantage  is  that  the  carriers  can  go  arouna 
both  the  driving-  and  tightening-gear  without  the  necessity  of 
m  m  m m  _ 


UU  Hi  HI 


FIG.  105. 

having  terminal  stations,  as  in  the  former  case.  The  driving 
wheel  is  generally  in  the  form  of  a  special  clip-drum,  and  the 
terminal  wheel,  where  the  tightening  takes  place,  is  arranged  so 
that  the  passing  round  of  the  carriers  is  easily  effected. 

The  unloading  of  the  material  is  easily  done  by  allowing  the 
carrier  to  strike  a  catch,  causing  the  bucket  to  capsize  or  open  at 
the  bottom.  The  loading,  however,  is  more  complicated,  and 
many  devices  have  been  devised  for  this  purpose  which  chiefly 
consist  in  hoppers  located  near  the  terminal  station  discharging 
into  the  carriers  and  moving  with  them  and  returning  immedi- 
ately to  their  former  position  so  .as  to  be  ready  for  a  new  carrier. 

The  Hodgson  and  Hallidie    system   is  very  convenient  for 


224  EARTH  AND  ROCK  EXCAVATION. 

carrying  continuously  materials  over  ridges  of  great  elevation, 
and  where  sudden  and  frequent  changes  of  level  have  to  be  oper- 
ated over.  The  Bullivant  Company,  Ltd.,  after 
designs  of  Mr.  Carrington,  who  was  an  associate 
of  Mr.  Hodgson,  and  from  whom  we  have 
obtained  the  present  description  and  informa- 
tion, has  built  a  ropeway  of  the  Hodgson  system 
in  Japan,  carrying  materials  up  a  mountainside 
which  has  an  incline  of  1  in  1£,  the  length  of 
FIG.  106.  the  road  being  nearly  one  mile.  The  diagram 

given  in  Fig.  105  indicates  both  in  front  view  and  plan  the  man- 
ner of  working  of  the  Hallidie  and  Hodgson  systems  of  ropeway. 
Fig.  106  shows  a  carrier  for  use  with  this  kind  of  ropeway  suitable 
for  carrying  earth,  sand,  crushed  stone,  and  in  general  any  rock 
material. 

One  of  the  most  efficient  grips  for 
connecting  the  bucket  to  the  traveling 
rope  is  the  Brown  Aerial  Tramway  Clip, 
controlled  by  Broderick  &  Bascom  of 
St.  Louis,  indicated  in  Fig.  107.  The 
grip  consists  of  three  forged  strap-bands 
encircling  the  rope,  and  the  bucket  is  sus-  FIG.  107. 

pended  to  a  yoke  hinged  to  the  strap-bands. 

The  Otto,  Bleickert,  Broderick,  and  Similar  Cableways. — These 
are  all  constructed  on  the  principle  in  which  several  carriers  run 
at  the  same  time  on  an  endless  fixed  rope  used  as  a  trackway, 
while  they  are  moved  along  by  means  of  an  endless  hauling- 
rope. 

The  cable-track  is  supported  at  different  points,  and  the  entire 
line  is  thus  divided  into  various  spans.  In  these  systems  of  aerial- 
ways  the  cables  are  very  tightly  stretched,  thus  securing  to  the 
loads  a  comparatively  direct  path,  which  means  that  they  are  not 
subjected  to  great  fluctuations  of  rise  and  fall  or  wave  motion. 
On  each  line  there  are  two  track-cables,  one  for  the  loaded  skips 
and  the  other  for  the  return  of  the  empty  ones.  The  lines  are 
parallel  and  placed  at  such  a  distance  as  to  prevent  the  carriers 
loaded  with  materials  and  running  in  one  direction  from  inter- 


TRANSPORTING    EXCAVATED    MATERIALS    BY    CABLEWAYS.     225 


fering  with  the  empty  ones,  running  in  the  opposite  direction. 
As  a  rule  the  ropes  are  pladed  7  ft.  apart. 

The  track-cable  is  made  Stationary  by  means  of  intermediate 
supports  placed  at  distances  varying  from  150  to  200  ft.  apart. 
These  consist  of  high  posts  having  a  crosspiece  on  top  for  the 
support  of  the-  track-cables.  The  crosspiece  is  made  stiff  by 
two  struts  abutting  against  the  post,  and  to  increase  the  sta- 
bility of  the  post  two  wooden  stays  are  placed  so  as  to  enlarge 
its  base.  With  greater  spans  the  supports  are  on  especially  con- 
structed towers.  Since  the  cables  are  supported  continuously 
along  the  line,  these  cableways  can  be  made  of  any  length.  Thus, 
for  instance,  there  is  a  cable  way  of  the  Bleickert  system  hi  Syra- 
cuse, N.  Y.,  which  is  16,500  ft.  long,  and  the  one  built  across  and 
over  the  famous  Chilcott  Pass  in  Alaska  is  9  miles  long.  Lately 
Leschen  of  St.  Louis  built  a  cableway  over  16  miles  long  for  the 
transportation  of  the  minerals  of  the  North  American  Copper  Co.  at 
Encampment,  Wyo.  Another  long  cableway  founded  on  this  prin- 
ciple was  built  by  the  Otto  Company  in  the  year  1888  in  Spain,  over 
a  country  impassable  to  any  other  means  of  transportation.  It 
was  constructed  to  convey  the  ore  from  the  Serena  de  Bedar  to 
the  seacoast  of  Garruche.  On  this  line  there  are  gradients  of  1  to 
3,  and  spans  of  nearly  1000  ft. 

The    end-stations    (Fig.    108)    are    provided   with   horizontal 

Carrying- 
Traction 
Rope 


Elevation 
FIG.   108. 


sheaves  for  the  continuous  revolving  of  the  endless  traction-rope, 
which  is  obtained  by  connecting  the  shaft  of  one  of  the  sheaves 
with  a  driving-engine  located  near  by.  The  carrying  rope  is  con- 


226 


EARTH    AND    ROCK    EXCAVATION. 


nected  with  an  iron  loop  upon  which  the  cars  are  run  after  having 
been  automatically  detached  from  the  traction -rope.  The  cars 
are  automatically  loaded  and  unloaded,  and  brought  back  to  be 
attached  again  to  the  traction-rope. 

The  complete  carrier  used  with  this  system  consists  of  a  car- 
riage (Fig.  109)  which  is  made  up  of  two  grooved  wheels  having 

in  their  middle  a  pivoted  hanger  which 
supports  the  bucket.  The  hanger  is 
constructed  in  such  a  way  as  to  allow 
the  passage  of  the  carriage  over  the 
supports  without  interfering  with  them. 
The  carrier  is  attached  to  the  traction 
rope  by  means  of  a  grip.  When  the 
cars  arrive  at  either  terminal,  or  other 
station,  the  grips  detach  automatically, 
and  the  carriages  are  switched  off  onto 
the  shunt-rails,  supported  by  the  structure 
of  the  station.  It  is  generally  during  the 
running  of  the  cars  onto  these  shunt- 
rails  that  they  are  automatically  loaded 
FIG.  109.  or  discharged  as  the  case  may  be. 

The  differences  between  the  Otto,  Bleickert,  Leschen,  and  other 
similar  systems,  although  magnified  and  highly  praised  by  the 
various  manufacturers,  are  not  important  for  those  who  consider 
the  cableways  from  a  general  point  of  view  of  hauling  apparatus. 
The  differences  chiefly  consist  in  the  form  of  carriages  and  hangers, 
in  the  grips  of  the  hauling-rope,  in  the  saddles  supporting  the 
cable-tracks,  in  the  manner  of  shifting  the  carriers  from  the  rope- 
way to  the  shunt-rails,  in  the  manner  of  loading  and  unloading 
the  cars,  etc.  All  these  details  must  be  examined  with  great  care 
by  the  engineers  and  contractors  before  deciding  which  machine 
to  buy,  and  which  would  be  the  most  appropriate  one  in  the  par- 
ticular case  that  he  has  to  deal  with. 

This  system  of  cableway,  in  which  the  carriers  run  on  an  endless 
fixed  rope  and  are  moved  along  by  means  of  a  hauling-rope,  is 
convenient  for  the  transportation  of  not  less  than  400  tons  of 


TRANSPORTING  -EXCAVATED    MATERIALS    BY    CABLEWAYS.     227 

materials  per  day,  and  over  rough  country  where  the  inclines 
exceed  1  in  3  and  the  span|  exceed  600  ft.;  and  also  when  the 
single  load  of  the  bucket  exceeds  6  cwt.  In  general,  the  great 
advantage  of  this  system  consists  in  relieving  the  traction-rope 
of  the  weight  of  the  loads,  so  that  on  comparatively  level  lines 
the  tension'  upon  the  traction-rope  is  but  little  more  than  the 
tractive  force  required  to  move  the  load.  In  fact  on  level  and 
regular  ground  the  motive  power  necessary  to  haul  one  ton  can 
be  assumed  at  |  H.P.  per  mile.  As  a  rule,  these  systems  of 
transportations  are  very  convenient  in  mining  where  large  quanti- 
ties of  material  must  be  hauled  every  day,  and  where  the  country 
is  usually  so  hilly  that  any  other  means  of  hauling  will  be  far 
more  expensive.  But  they  are  never  used  and  are  not  conve- 
nient in  the  excavation  of  earth  for  public  works. 

This  system  of  cableways  is  economical  in  wear  and  tear,  but 
the  first  cost  is  greater  than  in  the  other  two  already  indicated. 
This  will,  however,  be  very  efficient  when  the  daily  quantity  of 
material  to  be  transported  is  large,  because  in  such  cases  the  cost 
per  unit  of  volume  of  the  material  will  be  greatly  reduced.  The  cost 
of  working  a  cableway  of  the  Otto  system  of  the  capacity  of  500 
tons  per  day  is  about  IcL  per  mile,  and  including  repairs,  interest 
on  capital,  and  depreciation,  about  l\d.  per  ton  per  mile.  For 
another  Otto  ropeway  at  Esch  in  Luxemburg,  which  is  three  miles 
in  length  and  transports  300  tons  of  ore  per  day  of  ten  hours,  the 
cost  of  transport  including  all  expenses,  viz.,  wages,  repairs,  inter- 
est on  capital  and  depreciation,  works  out  to  only  4Jd  per  ton 
or  l^d.  per  ton  per  mile. 

All  these  systems  of  ropeways  so  far  reviewed  have  an  inherent 
defect,  says  Mr.  S.  W.  White,  of  the  firm  R.  White  &  Sons,  of 
Widnes,  Lancashire,  England,  a  defect  that  so  far  has  largely 
militated  against  their  usefulness.  They  must  all  go  in  a  direct 
straight  line  from  end  to  end,  and  if  a  corner  must  be  turned,  an 
angle-station,  With  one  or  two  attendants,  has  to  be  provided. 
And  further,  the  carrying-rope  used  (whether  on  the  single-  or 
double-rope  principle)  has  to  be  long  and  strong  enough  to  carry 
the  weight  of  the  whole  aggregate  load  on  the  line  at  once,  less  a 


228  EARTH  AND  ROCK  EXCAVATION. 

certain  percentage  for  saddle  friction,  and  consequently  ropeways 
have  only  been  able  to  carry  relatively  small  loads  with  small 
output.  To  avoid  these  inconveniences  Mr.  White  has  patented 
a  system  in  which  are  used  separate  ropes  for  every  span,  so  that 
heavy  individual  loads  of  1  or  2  tons  each  can  be  easily  carried, 
and  the  loads  can  also  turn  corners  at  every  span  if  necessary,  and 
without  any  extra  cost. 

Fixed  Cable  Track  with  Endless  Hauling-rope.  —  The  method 
of  hauling  materials  by  means  of  a  fixed  rope  in  which  only  one 
carrier  is  employed  hanging  from  it  and  moved  along  the  cable 
by  means  of  a  thinner  hauling-rope,  is  more  important  to  engineers 
and  contractors,  being  the  only  system  used  in  the  ordinary 
excavation  of  earth  required  for  the  execution  of  public  works. 
This  method  was  at  first  introduced  by  Mr.  W.  Carrington,  and 
afterward  greatly  modified  and  improved.  It  will  be  convenient 
to  study  these  cableways  in  two  separate  groups.  The  first 
includes  those  acting  as  a  simple  means  of  transportation  as  orig- 
inally derived  by  Mr.  Carrington,  and  the  second  includes  cable- 
ways  operating  as  hoisting-  and  convey  ing-machines.  The  cable- 
ways  of  the  first  group  find  convenient  employment  in  the 
industries,  but  those  of  the  second  that  are  now  extensively  used 
on  public  works. 

The  cableways  of  the  first  group  are  composed  of  one  single 
fixed  rope  to  which  one  carrier  is  suspended  and  is  moved  back 
and  forth  by  means  of  an  endless  hauling-rope.  This  endless 
rope  is  commanded  by  an  engine  provided  with  reversible  motion, 
so  that  the  direction  in  which  the  carrier  runs  may  be  changed 
by  the  operator.  The  fixed  rope  is  supported  on  posts  at  inter- 
vals of  about  300  ft.,  and  the  hauling-rope  is  carried  on  pulleys 
fitted  with  guide-bars,  placed  in  the  center  of  the  post  over  which 
the  carrier  passes,  the  posts  being  arranged  so  as  to  allow  of  the 
carriers  passing  through  them.  The  return  hauling-rope  is  sup- 
ported on  an  outside  pulley  mounted  on  an  arm  of  each  post. 
The  hauling-rope  is  attached  to  the  carrier-head  by  a  peculiarly 
shaped  pendant  which  causes  it  to  pass  under  the  saddle  transom. 

With  this  system,  Mr.  Carrington  says,  inclines  up  to  1  in  1 


TRANSPORTING    EXCAVATED   MATERIALS    BY    CABLEWAYS.     229 


or  even  steeper  can  be  worked,  spans  up  to  2000  yds.  may  be 
operated,  and  loads  up  to  5  "tons  may  be  dealt  with. 


FIG.  110. 


Fig.  110  shows  the  general  arrangement  of  this  kind  of  cable- 
way,  indicating  the  end  tower  and  the  single 
traveling  bucket  supported  by  the  fixed 
rope  and  carried  along  by  the  traction  rope. 
Fig.  Ill  shows  the  post  with  fixed  rope  in 
position  when  the  carrier  is  not  passing. 

The  single  fixed-rope  cableways  used 
in  public  works  have  only  one  span  and, 
besides  the  hauling-rope  which  moves  the 
carriage  back  and  forth,  are  provided  with 
a  second  rope  by  means  of  which  the  load 
can  be  raised  or  lowered  at  the  will  of 
the  operator.  These  cableways  are  really 
hoisting-  and  conveying-machines,  and  are 
found  in  great  numbers  on  the  market  with 
different  names,  as  the  Floory,  the  Carson,  the  Roebling,  the 
Locke  &  Miller,  etc.  They  are  all  founded  on  the  same  principle, 


FIG.  111. 


230  EARTH  AND  ROCK  EXCAVATION. 

but  vary  greatly  in  their  details;  some  are  very  simple,  as  the 
Carson.  trenching-machine,  and  others  quite  complicated,  as  the 
Locke  &  Miller;  and  in  order  to  avoid  useless  descriptions,  only 
these  two  types  of  hoisting-  and  conveying-machines  will  be 
illustrated  here. 

The  Carson  trenching-machine  takes  its  name  from  Mr.  How- 
ard A.  Carson,  the  chief  engineer  of  the  Boston  Transit  Commis- 
sion. It  is  called  a  trenching-machine,  because  it  was  designed 
by  Mr.  Carson  while  he  was  general  superintendent  of  the  sewers 
of  Boston,  for  the  hoisting  and  conveying  of  materials  to  and 
from  the  bottom  of  trenches.  The  Carson  cableway  is  made  up 
of  a  track-rope  fixed  to  the  ground  and  supported  by  means  of 
two  A  frames.  The  track-cable,  whose  diameter  varies  from  1J 
to  2J  ins.  in  diameter,  is  fixed  to  the  ground  by  means  of  what 
are  commonly  called  the  dead  men.  These  consist  of  wooden 
beams  from  6  to  8  or  even  10  ins.  in  diameter,  and  around  which 
is  looped  the  rope  in  the  manner  represented  in  Fig.  112.  To 


FIG.  112. 

prevent  any  movement  of  the  beam  and  consequently  of  the 
attached  rope,  the  ends  of  the  beams  are  buried  under  piles  of 
stone  or  other  material.  The  A  frames  supporting  the  track-rope 
are  located  at  the  extremities  of  the  system  150,  200,  and  even 
more  feet  apart.  They  are  called  A  frames  on  account  of  their 
similarity  to  the  letter  A.  They  are  made  up  of  square  beams 
6X6  ins.  or  8X8  ins.,  and  in  the  manner  indicated  in  Fig.  113. 
On  top  of  the  cap-pieces  there  is  an  iron  saddle  for  the  support  of 
the  cable.  At  the  front  frame,  just  underneath  the  cap-piece 
and  between  the  two  inclined  beams  of  the  frame,  there  are  three 


TRANSPORTING    EXCAVATED    MATERIALS    BY    CABLEWAYS.     231 


pulleys — one  for  the  hoisting-rope  and  two  for  the  hauling-rope. 
At  the  rear  frame  there  is  ah  inclined  sheave  for  the  return  of  the 


Hear 


FIG.  113. 


hauling-rope;  it  is  placed  in  an  inclined  position  in  order  to  allow 
the  returning  hauling-rope  to  pass  on  one  side  of  the  carriage. 
The  front  frame  is  connected  with  a  wooden  platform  upon  which 
is  located  the  boiler  and  a  double-drum  reversible  engine  for 
operating  the  cable  way. 


FIG.  114. 


The  carriage  (Fig.  114)  is  composed  of  two  grooved  wheels  for 
running  on  the  track-cable;  the  front  wheel  is  the  larger,  and 
they  are  connected  by  means  of  iron  bands.  Below  the  smaller 
wheel  of  the  truck,  by  means  of  two  vertical  iron  bands,  is  sup- 


232  EARTH  AND  ROCK  EXCAVATION. 

ported  the  large  hoisting-sheave  with  a  very  small  one  between 
them  for  the  support  of  the  hauling-rope,  while  below  the  larger 
front  wheel  of  the  truck  there  is  a  small  sheave  for  the  support 
of  the  hauling-rope. 

The  hauling-rope  is  attached  to  the  front  end  of  the  carriage, 
and  passing  over  one  of  the  sheaves  of  the  head  frame  goes  around 
one  of  the  drums  of  the  reversible  engine.  It  then  passes  over 
a  second  sheave  of  the  head  A  frame,  and  through  the  carriage 
over  the  two  smallest  wheels,  thence  over  the  inclined  sheave  of 
the  rear  A  frame,  and  returns  and  is  tied  to  the  rear  end  of  the 
carriage  and  near  the  hoisting- wheel.  One  end  of  the  hoisting- 
rope  is  tied  to  the  front  of  the  carriage,  and  it  supports  a  fall- 
block  to  which  the  bucket  is  attached,  and  then  passing  over  the 
large  hoisting-wheel  of  the  carriage  returns  over  a  sheave  at  the 
head-tower  and  around  the  second  drum  of  the  hoisting-engine. 
By  turning  either  way  the  first  drum  of  the  engine,  the  carriage 
is  moved  back  and  forth  along  the  rope  trackway,  and  by  loosen- 
ing the  rope  commanded  by  the  second  drum  the  fall-block  is 
lowered,  and  consequently  the  skip  or  bucket  attached  to  it  can 
be  lowered  to  the  bottom  of  the  trench.  By  reversing  the  drum 
the  attached  bucket  is  raised  to  a  convenient  height,  so  that  it 
may  travel  along  the  ropeway  without  any  interference.  Thus 
Carson's  trenching-machine  is  really  a  hoisting  and  conveying 
apparatus. 

The  efficiency  of  the  machine  is  assumed  at  600  cu.  yds.  per 
day,  and  since  the  running  expenses  of  the  apparatus  can  be 
assumed  at  $12,  the  cost  of  hoisting  and  coirv^ing,  a  unit  of 
volume  of  the  excavated  earth  is  2  cents  per  cu.  yd. 

Carson's  trenching-machines  have  been  extensively  employed 
in  the  construction  of  the  New  York  rapid-transit  railway,  and 
all  the  subcontractors  have  unanimously  declared  that  it  is  the 
simplest  and  most  economical  device  for  handling  earth  and  rock 
from  the  bottom  of  trenches  to  the  ground-surface. 

This  simple  hoisting  and  conveying  device  cannot  be  employed 
with  spans  longer  than  200  or  300  ft.  For  longer  spans  it  is  neces- 
sary to  support  both  the  hoisting-  and  hauling-rope,  and  for  such 


TRANSPORTING   -EXCAVATED    MATERIALS    BY   CABLEWAYS.     233 

a  purpose  the  fall-rope  carriers  are  introduced,  and  since  these 
are  employed  at  some  distance  apart  there  is  used  another  rope 
which  is  called  a  button-rope.  One  of  the  most  complicated  but 
extensively  used  cableways  of  this  type,  which  on  account  of 
its  particular  construction  can  be  used  with  spans  of  even  2000  ft. 
and  for  carrying  weights  of  even  5  tons  each,  is  the  Locke-Miller 
cableway,  whose  description  is  given  below. 

The  Locke-Miller  Cableway. — The  following  is  a  description  of 
the  Locke-Miller  patent  cableway  manufactured  by  the  Lidgerwood 
Manufacturing  Company  of  New  York.  The  main  cable  is  usually 
of  steel  wire,  and  is  suspended  from  towers  or  A  frames,  which 
may  be  from  200  to  1500  ft.  apart,  and  the  ends  are  securely 
anchored.  This  cable  is  used  on  a  trackway  upon  which  travels 
a  carriage  supporting  a  load,  which  may  be  either  raised  or  low- 
ered by  means  of  a  fall-block.  Three  additional  ropes  are  em- 
ployed in  this  style  of  cableway,  one  for  moving  the  carriage 
along  the  main  cable,  and  called  the  traversing-  or  endless  hauling- 
rope;  another  which  commands  the  fall-block  and  is  used  for 
hoisting  the  load,  and  is  called  the  hoisting-  or  fall-rope;  and  a 
third  or  button-rope,  introduced  in  order  to  place  the  fall-rope 
carriers  from  the  carriage  at  regular  intervals  along  the  cable. 


imppsN 

FIG.  114a. 

The  power  for  operating  this  cableway  consists  of  a  specially 
constructed  engine  represented  in  Fig.  114a.  This  is  provided 
with  double  cylinders,  reversible  link-motion,  and  friction-drums 
and  brakes.  Both  drums  are  of  precisely  the  same  diameter,  but 


234  EARTH  AND  ROCK  EXCAVATION. 

one  is  narrow  and  of  a  curved  form  to  receive  the  traversing  or 
endless  rope,  and  the  other  drum  is  wider  and  spirally  grooved 
for  the  hoisting-rope.  The  endless  hauling-rope  is  turned  three 
or  four  times  around  the  drum  so  as  to  secure  sufficient  friction 
to  keep  it  from  slipping  in  a  direction  opposite  to  the  one  in  which 
the  drum  is  turning,  and  this  hauling-rope,  after  passing  over  the 
sheaves  on  top  of  the  A  frames  or  towers,  is  made  fast  to  the  front 
and  rear  of  the  carriage.  As  the  engine  is  made  reversible  by 
turning  the  drum  forward  or  back,  the  carriage  is  pulled  along 
the  fixed  cable-track  in  either  direction  at  will.  The  hauling-rope 
attached  to  the  carriage  is  supported  by  the  fall-rope  carriers. 

The  hoisting-rope  goes  from  its  drum  on  the  engine  to  the 
carriage,  and  there  it  connects  with  the  fall-block,  usually  by  a 
three-part  purchase  and  in  the  manner  indicated  in  Fig.  115,  in 
which  are  clearly  shown  the  various  ropes  of  the  Locke-Miller 
cable  way.  The  hoisting-rope  is  supported  by  a  system  of  fall- 
rope  carriers,  upon  which  the  successful  operation  of  the  whole 
cableway  depends.  These  carriers  are  of  wrought  iron  and  are 
made  light  and  strong  and  are  provided  with  suitable  wheels  for 
the  support  of  both  the  hauling-  and  hoisting-ropes.  They  ride 
on  the  horn  on  front  of  the  carriage  until  they  are  displaced  by 
means  of  steel  buttons  located  on  the  button-rope,  so  that  each 
button  will  pass  through  every  carrier  except  one,  and  this  will 
be  pulled  off  the  horn  of  the  carriage.  As  these  buttons  are  located 
at  regular  intervals  along  the  button-rope,  it  is  evident  that  at 
each  button  a  carrier  will  be  displaced  from  the  horn  of  the  car- 
riage as  this  is  passing  along.  In  this  way  both  the  hoisting-  and 
hauling-ropes  are  supported  all  along  the  line.  When  the  carriage 
moves  in  the  opposite  direction,  the  carriers  will  be  picked  up  by  the 
projection  of  the  horn  on  the  carriages  as  fast  as  they  are  reached. 

Fig.  1.16  shows  the  special  form  of  carriage  designed  for  the 
operation  of  the  Locke-Miller  cableway.  It  is  made  in  a  sub- 
stantial manner  of  wrought  iron,  and  yet  it  is  comparatively 
light.  The  running-wheels  are  of  cast  iron  with  deep  flanges, 
and  have  anti-friction  bearings  so  as  to  run  as  easily  as  possible 
on  the  cable.  The  hoisting- wheels  are  also  of  cast  iron,  and  of 


TRANSPORTING    EXCAVATED    MATERIALS    BY    CABLEWAYS.     235 


large  diameter,  to  reduce  the  wear  on  the  hoisting-rope,  and  also 
to  enable  the  fall-block  to  lower  as  freely  as  possible.  The  fall- 
block  is  specially  constructed  ^or  cableway  work,  has  wrought- 
iron  sides  and  anti-friction  bearings,  and  is  made  as  light  as  com- 


1:          J 


FIG.  115. 

patible  with  strength  and  overhauling  the  hoisting-rope,  so  that  it 
may  be  easily  handled.  The  purchase  used  is  generally  three  parts, 
but  it  may  have  one,  two,  four,  or  even  more  parts  if  necessary. 

The  entire  operation  of  this  cableway  is  under  the  absolute 
control  of  the  engineer,  who  with  a  little  practice  can  work  the 
cableway  so  accurately  as  to  even  lay  cut  stones  with  perfect 
ease.  It  is  thus  well  adapted  for  the  construction  of  dams,  long 
walls,  breakwaters,  etc.  It  is  very  valuable  in  public  works  for 


236 


EARTH    AND    ROCK    EXCAVATION. 


the  economical  handling  of  materials,  and  it  is  of  special  value  in 
the  excavation  of  rock,  since  it  is  out  of  the  reach  of  a  blast.  This 
cableway  is  used  with  great  success  in  all  kinds  of  quarry  work, 
where  loads  of  15  tons  are  picked  up  in  the  quarry  and  landed 


FIG.  116. 

on  cars  with  perfect  ease  and  at  a  speed  hitherto  unknown.  With 
a  Locke-Miller  cableway,  1350-ft.  span,  designed  for  a  6J  ton  load, 
with  a  steel  cable  2J  ins.  in  diameter,  loads  of  from  7  to  8  tons 
weight  were  easily  handled  at  a  speed  of  600  to  800  ft.  per  minute. 
The  daily  cost  of  working  the  Locke-Miller  cableway  is  given 
by  the  Lidgerwood  Manufacturing  Company,  the  builders,  as 
follows : 

3  men  to  operate  the  conveyor,  at  $1 . 50 $4 . 50 

1  engineer,  at  $3.50 3.50 

1  fireman,  at  $1 .75 1 .75 

1  signalman,  at  $1 . 50 1 . 50 

Coal 4.00 

Oil  and  waste 50 

$15.75 


TRANSPORTING    EXCAVATED    MATERIALS    BY    CABLEWAYS.     237 

To  this  amount  should  be  adcjed  the  wage  of  a  laborer  employed 
to  oil  and  clean  the  apparatus.  This,  however,  is  exclusive  of 
the  cost  of  labor  for  Joading  *he  buckets,  an  item  which  cannot 
be  charged  to  the  conveyor.  On  Section  8  of  the  Chicago  Drain- 
age Canal  a  total  of  344.175  cu.  yds.  of  rock  were  removed  by 
this  kind  of  cableway  acting  as  a  hoisting-  and  conveying- 
machine.  The  cost  was  3.56  cents  per  cu.  yd. 

Movable  Cableways. — A  great  advantage  in  connection  with 
this  system  of  ropeways,  in  which  only  one  carrier  travels  back  and 
forth  on  a  fixed  rope  moved  along  by  an  endless  hauling-rope,  is 
that  the  towers  supporting  the  rope  can  be  placed  upon  wheels 
and  consequently  the  whole  machine  can  be  moved  in  a  direction 
either  parallel  or  perpendicular  to  the  rope.  In  such  a  case  the 
two  ends  of  the  fixed  carrying-rope,  instead  of  being  held  in  posi- 
tion by  dead-men,  as  indicated  above,  are  firmly  fixed  at  the 
extremes  of  the  platforms  supporting  the  towers.  The  Carsons 
trenching-machine  and  other  similar  simple  cableways,  when 
moving  in  a  direction  parallel  to  the  carrying-rope,  are  very  con- 
venient in  the  excavatibn  of  trenches  and  for  laying  pipes  under 
city  streets,  and  when  moving  in  a  direction  perpendicular  to  the 
carrying-rope  are  very  convenient  for  the  excavation  of  canals,, 
roads,  and  other  similar  structures  having  considerable  width 
and  much  greater  length. 

In  the  excavation  of  the  Chicago  Drainage  Canal  it  became 
necessary  to  use  some  device  by  which  the  material  could  be 
rapidly  hoisted  and  conveyed  to  the  spoil-bank  and  yet  that  was 
sufficiently  portable  to  travel  along  the  banks  as  fast  as  the  work 
progressed.  Accordingly  the  Lidgerwood  Manufacturing  Com- 
pany patented  a  traveling  cableway  which  was  very  advanta- 
geously employed  in  various  sections  of  that  important  work.  Not- 
withstanding that  Engineering,  Vol.  LXIII,  p.  271,  claims  that  the 
invention  is  due  to  a  French  engineer  named  Pluchet,  who  about 
half  a  century  ago  patented  a  cableway  for  canal  construction 
which  traveled  along  the  banks  after  the  manner  of  the  Lidger- 
wood apparatus,  it  is  highly  improbable  that  the  original  system 


238  EARTH  AND  ROCK  EXCAVATION. 

was  ever  used,  and   credit  is   due  to  the  Lidgerwood   Company 
for  the  first  application  of  this  system. 

It  was  a  cableway  of  the  type  being  considered,  having  one 
fixed  carrying-rope  and  provided  with  only  one  large  bucket, 
which  could  be  moved  back  and  forth  by  means  of  a  hauling- 
rope,  and  also  raised  up  or  lowered  by  means  of  a  hoisting-rope. 
The  span  of  this  cableway  was  700  ft.  and  the  load  to  be  carried 
varied  from  5  to  8  tons.  The  head  tower  was  92  ft.  high  and 
mounted  on  a  car  44  ft.  wide  and  108  ft.  long.  The  tail  tower 
was  72  ft.  high  and  mounted  on  a  car  37  ft.  wide  and  82  ft.  long. 
These  cars  were  supported  on  a  suitable  number  of  railway  wheels 
of  standard  gauge  and  each  car  ran  on  three  tracks.  In  order 
to  insure  proper  stability  these  cars  were  heavily  ballasted  with 
stones  on  the  outside.  The  tail  tower  was  located  close  to  the 
channel,  while  the  head  tower  was  beyond  both  the  channel  and 
spoil-bank,  as  indicated  in  Fig.  117.  The  cars  were  moved  back 


FIG.  117. 

and  forth  on  the  trackway  by  means  of  ropes  commanded  by  two 
small  winch-engines. 

The  cableway  was  of  the  ordinary  Locke-Miller  type  and 
perfectly  identical  to  the  horizontal  fixed  cableway  described 
above,  the  only  exception  being  the  aerial  dump  by  which  the 
loaded  skip  was  dumped  while  moving  through  the  air  and  pass- 
ing above  the  spoil-bank.  This  is  clearly  indicated  in  Fig.  118, 
taken  from  an  instantaneous  photograph.  This  operation  was 
obtained  by  means  of  an  auxiliary  rope  running  from  the  hoisting- 
drum  of  the  engine  over  the  carriage,  and  attached  to  the  third 


TRANSPORTING    EXCAVATED    MATERIALS    BY    CABLEWAYS.     239 

chain  of  the  skip.  As  the  carriage  approached  the  head- tower 
this  rope  was  drawn  in  at  a  Jsigher  rate  of  speed,  thus  raising  the 
end  of  the  skip  and  spilling  the  load  entirely,  at  will  of  the  engineer 
and  while  the  carriage  was  in  motion.  The  engine  was  then 
instantly  reversed  and  the  carriage  went  back  over  the  canal, 


FIG.  118. 

the  empty  skip  which  had  resumed  its  horizontal  position  was 
lowered  and  unfastened,  and  the  chains  hooked  to  a  full  skip. 

The  daily  capacity  of  this  movable  cable  way  was  about  600  eu. 
yds.  of  rock  per  day,  and  the  average  distance  of  the  haul  was 
about  300  ft.  The  skips  contained  about  2  cu.  yds.  of  stone. 
Single  rocks  of  nearly  4  cu.  yds.  have  been  easily  handled.  The 
cost  of  hauling  the  material  by  means  of  movable  cableways  on 
the  8th  Section  of  the  Chicago  Canal  was  3.56  cents  per  cu.  yd. 

Inclined  Cableways. — All  the  various  systems  of  cableways 
described  are  generally  employed  for  horizontal  roads,  although 


240  EARTH  AND  ROCK  EXCAVATION. 

they  are  also  used  on  inclined  lines;  but  when  the  inclination  is 
too  great  cableways  of  special  construction  are  usually  employed. 
Inclined  cableways  can  be  used  either  as  a  simple  means  of  trans- 
portation, or  as  a  hoisting-  and  conveying-machine ;  the  former 
are  known  as  "  shoots,"  and  the  latter  are  called  inclined  cable- 
ways. 

Shoots. — Shoots,  Mr.  Carrington  says,  consist  of  one  fixed  rope 
placed  on  an  incline  on  which  the  carriers,  from  which  the  loads 
are  suspended,  are  allowed  to  run  down  uncontrolled  one  at  a 
time.  It  is  a  system  of  a  simple  nature,  and  is  used  for  the  trans- 
port of  undamageable  goods.  It  consists  of  a  light  wire  rope 
stretched  between  two  points,  the  elevation  of  one  being  consid- 
erably above  that  of  the  other.  On  this,  loads  from  1  cwt.  to  4 
•cwt.,  hanging  from  a  runner  carrying  one  or  two  wheels,  are  allowed 
to  run  down  uncontrolled.  At  the  lower  end  brushwood,  or  other 
convenient  means,  are  provided  to  absorb  the  force  produced 
by  the  running  load  when  it  arrives  at  the  lower  terminal.  This 
can  be  considerably  lessened  by  regulating  the  sag  of  the  rope 
where  the  section  of  ground  will  admit,  so  as  to  reduce  the  speed 
of  the  runner  with  its  load  as  it  approaches  the  lower  terminal. 
Such  a  type  of  cableway  is  largely  used  for  the  carriage  of  fire- 
wood, coffee,  or  other  like  materials.  Spans  can  be  made  without 
support  up  to  7000  ft.,  and  all  that  is  required  for  fixing  the  rope 
is  a  good  anchorage  at  the  upper  end,  and  another  with  a  tighten- 
ing-gear  at  the  lower  end.  Ropes  for  this  purpose  up  to  3500-ft. 
spans  are  used,  made  in  the  form  of  a  strand;  above  this,  in  order 
to  obtain  the  necessary  strength  with  a  moderate  size  of  wire, 
ropes  are  used  consisting  of  several  strands  formed  each  of  several 
wires.  The  runners  have  wheels  of  small  diameter,  and  are  made  as 
light  as  possible  in  order  that,  after  50  or  100  loads  have  been  deliv- 
ered, the  empty  ones  may  be  carried  up  to  the  upper  end  for  a 
further  delivery  of  material. 

Inclined  Cableways. — The  inclined  cableways  used  as  hoisting- 
and  conveying-machines  are  similar  to  those  employed  on  hori- 
zontal lines,  as  the  Carson,  the  Floory,  the  Locke  &  Miller,  etc., 
with  the  difference  that  the  two  towers  supporting  the  main 


TRANSPORTING   EXCAVATED    MATERIALS    BY    CABLEWAYS.     241 


cable  are  not  at  the  same  level.  On  account  of  the  peculiar  form 
of  the  catenary  curve  of  the  main  cable,  it  is  necessary  to  intro- 
duce some  arrangements  forTiolding  the  carriage  at  the  required 
point,  so  as  to  lift  the  load  when  the  resistance  to  travel  up  the 
cable  is  less  than  the  strain  in  the  hoisting-rope.  This  is  obtained 
by  means  of  a  specially  constructed  carriage,  known  as  the  Harris- 
Miller  patented  inclined  cableway,  constructed  and  controlled  by 
the  Lidgerwood  Manufacturing  Company,  illustrated  in  Fig.  119. 
The  carriage  is  provided  with  hooks  and  the  main  cable  with  fixed 
stops.  In  operation  the  carriage  travels  down  the  cable  by 
gravity  until  it  reaches  the  stop  which  engages  the  hook  and 


BUTTON  ROPE 


MAIN  CABLE 


HOISTING  ROPE 


PALL  BLOCK. 


FIG.  119. 

releases  the  fall-block,  which  descends  to  the  ground  to  get  the 
load.  The  fall- block  with  the  attached  weight  is  then  hoisted 
until  the  carriage  is  reached.  The  arm  of  the  fall-block  then  enters 
the  carriage  and  is  hooked  fast,  releasing  at  the  same  time  the  hook 
connected  with  the  stop,  thus  permitting  the  carriage  to  travel 


242  EARTH  AND  ROCK  EXCAVATION. 

up  the  incline.  On  reaching  the  top  of  the  incline  the  carriage 
engages  the  fixed  hook,  and  at  the  same  time  the  arm  of  the  fall- 
block  is  released  and  the  load  may  be  lowered.  To  descend  again 
the  fall-block  is  hoisted  to  the  carriage,  and  the  arm  entering  it 
is  locked  fast  while  the  fixed  hook  which  holds  the  carriage  in 
position  is  released  by  means  of  a  hand-rope. 

On  these  inclined  cableways  there  are  only  three  ropes  instead 
of  five,  as  in  the  Locke  &  Miller  cableways;  these  are  the  main 
cable,  the  button-rope  for  the  release  of  the  fall-rope  carriers,  and 
the  hoisting- rope.  Also  the  carriage  is  much  simpler,  and  is 
designed  with  special  reference  to  lightness  and  strength.  It  is 
made  of  wrought  iron,  and  the  locking  mechanism  is  of  steel 
castings.  The  wheels  for  the  hoisting-rope  are  of  large  diameter. 
Fall-rope  carriers  are  of  wrought  iron,  and  their  function  is  to 
support  the  fall-rope  as  the  carriage  descends  the  incline.  They 
travel  on  the  special  horn  or  projection  at  the  rear  of  the  car- 
riage, and  when  they  reach  the  buttons  their  further  progress  is 
prevented  and  they  remain  each  at  its  corresponding  button, 
and  support  the  fall-rope,  until  the  carriage  in  returning  takes 
them  and  carries  them  up  the  incline  again.  The  fall-rope  carriers 
do  not  interfere  in  any  way  with  the  automatic  locking  mecha- 
nism of  the  carriage.  On  very  long  spans  a  series  of  carriers  are 
used,  but  up  to  250-ft.  span  only  one  carrier  is  required.  The 
load  for  this  inclined  cableway  is  3  tons  or  less. 


CHAPTER  XVII. 

TRANSPORTING  EXCAVATED  MATERIALS  BY  TELPHERAGE. 

IN  the  aerialways  just  described,  the  carriers  containing  the 
materials  are  moved  by  ropes.  Telpherage  is  a  system  of  trans- 
porting materials  on  aerialways,  where  the  carriers  are  moved 
by  electric  motors.  Telpherage  was  invented  by  Prof.  Fleming 
Jenkins  of  Edinburgh,  Scotland,  and  the  name  given  by  him  was 
derived  from  the  Greek  words  rshe  and  (frepcu',  tele  means  far,  and 
ferro  means  to  bear  or  carry.  Therefore  telpherage  means  far 
carrying. 

According  to  this  method,  the  carriers  travel  along  the  track- 
way by  means  of  a  truck  composed  of  two  wheels  arranged  in 
the  same  way  as  those  employed  in  cableways;  and  they  are  sim- 
ilarly suspended  from  the  truck.  The  trackway  may  be  com- 
posed either  of  rigid  beams  or  cables,  and  as  a  rule  two  trackways 
are  employed — one  for  the  travel  of  the  loaded  cars,  and  the  sec- 
ond for  the  return  of  the  empty  ones.  This  system  can  be  com- 
pared with  the  double-rope  system  of  cableway  already  described, 
the  only  difference  being  that  while  in  the  former  the  hauling  is 
done  by  means  of  a  special  rope,  here  instead  it  is  performed  by 
motors  located  on  all  the  cars  or  simply  on  a  few  motor-cars. 

The  electric  current  is  distributed  in  the  manner  indicated  in 
Fig.  120.  Several  carriers  are  connected  together  so  as  to  form  a 
train,  and  the  electric  motor  is  placed  at  the  center.  The  cable 
does  not  form  a  continuous  conductor  for  the  current,  but  is  di- 
vided into  sections  of  the  same  length  as  the  train.  Each  section 
is  separated  from  the  two  adjacent  ones,  and  they  are  connected 
with  those  in  front  and  back  in  the  manner  clearly  shown  in  the 
diagram.  According  to  this  arrangement  there  are  two  wires 

243 


244  EARTH  AND  ROCK  EXCAVATION. 

carrying  the  electric  current  which  cross  each  other  at  the  extrem- 
ities of  every  section.  Each  section  of  the  rope  is  consequently 
charged  with  a  different  kind  of  electricity.  The  length  of  the 
train  is  so  arranged  that  its  two  extremities  will  always  be  on  two 
different  sections  of  the  rope,  in  such  a  manner  that  they  close 
the  circuit  of  the  current.  When  the  rear  end  of  the  train  leaves 
one  section  which  is  charged  with  positive  electricity,  to  enter 
the  successive  which  is  negative,  the  front  end  of  the  train  that 
was  running  on  a  section  of  the  rope  charged  with  negative  elec- 
tricity, will  enter  the  successive  one  which  is  positive.  Such  an 
inversion  of  the  current  does  not  change,  however,  the  direction 


X 

-  X 

x    - 

r 

•  C~  —  •       _L 

~ 

M        >     F 
FIG,  120. 

of  the  motor.  Consequently  a  train  which  travels  automatically 
over  one  rope  is  never  interfered  with  by  the  trains  traveling 
either  in  the  opposite  direction  along  the  parallel  rope  by  following 
trains  in  the  same  direction  and  with  little  headway. 

Several  systems  of  telpherage  have  been  devised  on  this  prin- 
ciple. In  the  Jenkins,  Ayston,  and  Perry's  telpher  the  trackway 
is  formed  by  two  parallel  wire  cables  supported  by  posts,  and 
with  the  interruptions  arranged  in  the  manner  indicated  in  the 
diagram.  The  carriers  move  along  the  trackway,  being  sus- 
pended from  a  truck,  which  is  composed  of  two  small  wheels. 
The  motor  is  connected  to  the  electric  circuit  by  means  of  the 
two- wheels  at  the  front  and  rear  end  of  the  train.  The  motor 
communicates  movement  to  the  wheels  of  the  car  by  means  of 
belt  transmission.  The  inventors  have  devised  also  a  scheme  for 
preventing  one  train  from  reaching  another  by  means  of  an  addi- 
tional section,  which  is  open  or  closed  automatically  by  the  cars, 
and  when  a  train  is  on  this  dead  section  the  circuit  is  broken  off 
and  the  following  train  will  automatically  come  to  a  sudden  stop. 


TRANSPORTING    EXCAVATED    MATERIALS    BY    TELPHERAGE.    245 

This  telpherage  system  was  successfully  employed  at  Glinde 
on  a  line  one  mile  long,  whic*h  is  still  in  operation.  The  motor-car 
occupied  the  center  ef  a  ten*ar  train,  so  that  five  cars  were  in 
the  front  and  five  at  the  rear  of  the  motor-car.  The  capacity  of  the 
cars  is  100  Ibs.  each;  and  they  are  kept  at  the  same  distance 
from  one  another  by  means  of  connecting-rods. 

Somewhat  different  from  the  system  just  described  is  the  one 
used  at  present  and  controlled  by  the  United  Telpherage  Company 
of  20-22  Broad  Street,  New  York,  with  branches  in  all  the  principal 
cities  of  the  world.  The  following  description  is  taken  from  a 
paper  read  by  Charles  M.  Clark  at  the  meeting  of  the  American 
Institute  of  Electrical  Engineers,  New  York  and  Chicago,  April 
25,  1902. 

In  regard  to  the  construction  of  the  telpherage  system,  Mr. 
Clark  says  that  it  may  be  stated  that  the  track  is  made  of  cable 
either  of  standard  or  lock-coil  wire,  which  latter  has  a  strength 
approximating  95  per  cent,  that  of  the  solid  bar,  or  else  solid  rail, 
either  of  flat,  girder,  or  bulb  type.  The  cable-tracks  are  supported 
every  hundred  feet,  provided  it  is  convenient  to  erect  poles  or 
structures.  Where  there  are  deep  ravines  the  span  is  made  to 
correspond  with  the  distance,  and  can  be  made  of  any  reasonable 
length.  In  addition  to  the  track-cable,  upon  which  the  telpher 
runs,  there  is  also  what  is  known  as  the  suspension  cable,  to  which 
the  main  cable  is  suspended  by  means  of  hangers  to  prevent 
excessive  sagging.  The  sizes  of  the  cable,  hangers,  and  brackets 
vary,  depending  upon  the  weight  which  comes  upon  each  individual 
.span.  The  support  is  either  made  of  simple  poles  with  a  bracket, 
or  of  what  is  known  as  A  construction,  or  of  ordinary  cross-bents. 
Cable  construction  costs  less  than  solid  rail,  except  where  there 
are  many  switches,  in  which  cases  the  prices  of  solid  rail  and 
cable  approach  each  other.  In  general,  for  straight  lines,  cable 
is  recommended  except  where  the  weight  is  excessive. 

In  solid  rail  construction  the  supports  are  ordinarily  placed 
16  to  20  ft.  apart;  longer  spans  are  used  if  it  is  not  convenient  to 
erect  supports.  On  long  spans,  the  track  consists  of  a  girder-rail 
with  the  track  above  it.  Running  parallel  to  the  track-rail, 


246 


EARTH    AND    ROCK    EXCAVATION. 


either  above  or  at  the  side,  and  depending  upon  the  amount  of 
headroom,  are  stretched  one  or  more  tr olley- wires ;  one  wire,  if 
the  track  be  used  as  a  return.  If,  however,  it  is  desired  not  to 
use  the  tracks  as  a  return,  or  to  use  alternating  current,  two 
trolley-wires  are  employed. 

According  to  the  construction,  telphers  are  divided  into  three 
distinct  classes — center-bearing,  side-bearing,  and  alternate-bear- 
ing. The  center-bearing  has 
two  motors,  one  on  each  side 
of  the  track;  the  side-bearing 
(Fig.  121)  has  both  motors  on 
the  same  side,  and  the  alter- 
nate has  one  motor  upon  one 
side  of  the  track,  and  the  other 
motor  upon  the  other  side,  but 
not  upon  the  same  shaft. 

The  motors  are  water-proof 
and  dust-proof,  and  are  com- 
pound wound  for  automatic 
work.  When  a  telpherman  goes 

with  the  telpher,  the  series  winding  is  employed.  There  is  also  used 
a  special  coil  to  give  greater  torque  when  starting.  The  telpher 
is  placed  above  the  track,  thereby  keeping  the  motors  from  injury, 
while  there  is  also  no  danger  of  their  coming  in  contact  with  the 
carriers  or  being  otherwise  injured. 

The  hoist  (Fig.  122)  is  suspended  below  the  telpher,  or  some- 
times from  a  trailer  drawn  by  the  telpher.  Special  effort  has 
been  made  in  the  later  designs  of  hoists  to  use  as  little  headroom 
as  possible.  It  was  deemed  best  at  first  to  combine  the  telpher 
and  hoist  all  in  one,  but  there  were  so  many  cases  where  it  was 
necessary  to  use  the  telpher  alone  without  the  hoist,  and  also 
where  it  was  advisable  to  put  the  hoist  on  the  trailer  instead  of 
on  the  telpher,  experience  has  shown  it  to  be  better  to  have  the 
telpher  and  hoist  two  separate  pieces  of  apparatus. 

Two  distinct  types  of  brakes  are  used  on  telphers,  either  hand- 
brakes or  solenoid-brakes,  both  of  which  are  arranged  to  apply 


FIG.   121 


TRANSPORTING    EXCAVATED    MATERIALS    BY   TELPHERAGE.    247 


pressure  to  the  wheels  or  to  grip  the  track.  In  regard  to  the 
solenoid-brake  it  is  only  necessary  to  explain  that  it  works  auto- 
matically, the  solenoid  being 
placed  in  series  with  the  arma- 
ture. A  spring  normally  holds 
the  brake  on  the  wheel  or  the 
track.  If,  however,  from  any 
cause,  the  amount  of  current 
passing  through  the  solenoid  is 
reduced,  whether  by  means  of 
external  resistance  or  by  reason 
of  the  additional  counter-elec- 
tromotive force  generated  by 
the  armature  due  to  running  at 
a  high  speed,  the  solenoid  be- 
comes weakened  and  the  brake 
is  applied.  An  air-cushion  is 
arranged  so  that  the  brakes  will 
be  applied  gradually. 

It  is  often  advisable,  where 
a  large  amount  of  material  is  to 

be   carried,  especially  over  one  FlG   122 

track,  to  use  trailers.  These  con- 
sist generally  of  a  two-wheeled  truck,  below  which  is  suspended 
a  bucket  or  other  suitable  form  of  carrier,  or  even  the  hoist,  as 
the  case  may  require.  It  is  customary,  where  a  larger  amount  of 
material  is  to  be  carried,  to  arrange  a  long  train  carrying  as  much 
as  ten  tons.  The  order  of  procession  is  first  a  telpher  with  four 
or  five  trailers,  then  another  telpher  and  four  or  five  trailers,  and 
a  telpher  at  each  end.  The  placing  of  these  telphers  at  intervals 
greatly  adds  to  the  traction,  while  the  distribution  of  weight  over 
the  whole  span,  or  over  two  or  three  spans,  enables  much  lighter 
construction  to  be  used  for  the  same  capacity. 

In  automatic  lines  it  is  necessary  to  provide  appliances  whereby 
it  is  impossible  for  an  unskilled  operator  to  injure  the  telpher. 
In  order,  therefore,  to  provide  for  contingencies,  a  "dead  section" 


248  EARTH  AND  ROCK  EXCAVATION. 

is  placed  at  each  end  of  the  line,  the  middle  of  the  line  being  gen- 
erally left  alive.  Upon  closing  a  spring-switch,  the  dead  section 
is  energized  so  long  as  the  operator  keeps  his  hand  on  the  switch,, 
which  is  generally  only  a  few  seconds,  during  which  time  the 
telpher  passes  to  that  portion  of  the  line  which  is  always  alive. 
When  it  reaches  the  other  end  it  comes  upon  the  dead  section 
and  then  either  shoves  down  of  its  own  accord,  or  else  a  mechanical 
or  solenoid-brake  is  applied.  The  telpher  then  passes  under  the 
reversing  arrangement  and  it  is  therefore  reversed  either  with  no 
current  in  the  line,  or  else  with  a  high  resistance.  If  the  telpher 
is  at  the  further  end  of  the  line,  the  operator  at  the  near  end,  by 
closing  a  switch,  can  bring  it  back  to  him.  The  dead  sections  at 
the  end  of  the  line,  which  only  have  current  so  long  as  the  hand  is 
held  upon  the  spring-switch,  render  the  line  as  safe  as  possible 
against  the  telpher  coming  in  contact  with  the  terminal  posts. 
An  automatic  block  system  prevents  collision  of  telphers. 

In  regular  service  the  speed  varies  from  300  to  800  ft.  per  min- 
ute up  to  20  miles  per  hour,  or  even  more  when  required.  The 
lower  speeds  are  used  when  the  lines  are  short,  and  where  there 
are  many  curves,  particularly  for  factory  and  foundry  work. 
For  lines  running  across  the  country  a  speed  in  excess  of  20  miles 
per  hour  can  be  obtained,  but  with  the  higher  speeds  the  cost  of 
the  construction  increases,  certain  special  devices  being  necessary. 

Although  the  amount  of  power  can  be  easily  figured  out,  yet 
it  is  somewhat  in  the  nature  of  a  surprise  when  we  consider  that 
to  carry  half  a  ton  on  a  level  track,  at  a  speed  of  6  miles  per  hour, 
much  less  than  a  horse-power  is  required,  including  all  losses. 
The  absence  of  gearing,  the  motors  being  attached  directly  to 
the  driving-wheels,  gives  the  highest  efficiency  possible,  as  well  as 
freedom  from  noise.  The  actual  power  consumed  at  6  miles  per 
hour  for  1000  Ibs.  on  a  level  is  only  0.16  H. P.  It  is  therefore  seen 
that  ample  allowance  is  made  for  losses  and  extra  weights  not 
provided  for  in  the  load,  such  as  down-comes,  buckets,  or  carriers. 
The  power  required  increases  greatly  with  the  grade,  and  when 
this  reaches  certain  limits  it  is  deemed  advisable  to  use  gears  in 
order  to  reduce  the  weight  of  the  motors. 


TRANSPORTING  EXCAVATED  MATERIALS  BY  TELPHERAGE.  249 

An  important  feature  in  telpherage  is  the  capacity  of  the  line. 
There  are  two  factors  of  special  importance  in  relation  to  the 
capacity  of  the  line:  first,  the  speed;  and  second,  the  number  of 
telphers  and  trailers*  The  line  can  be  laid  out  with  one  telpher 
and  a  few  trailers.  More  telphers  or  trailers  may  be  added,  and} 
if  upon  a  single  line,  coupled  in  long  trains.  If  it  is  desired  to 
increase  still  further  the  capacity,  the  line  can  be  made  double; 
while,  if  desired,  the  carriers  may  also  be  made  continuous,  so  as 
to  take  boxes  and  barrels,  or  any  other  material,  as  fast  as  they 
can  be  delivered  to  the  carriers  of  the  telphers  and  trailers. 

The  flexibility  of  telpherage  in  regard  to  capacity  is  wonderful, 
and  is  a  most  important  feature.  In  fact,  it  may  be  said  that 
there  is  practically  no  limit  to  its  flexibility.  It  is  recorded  even 
a  capacity  of  250  tons  per  hour  carried  on  a  line  half  a  mile  long. 
There  is  no  other  means  of  transporting  materials  which  can  be 
operated  so  economically,  cheaply,  and  in  so  thoroughly  satis- 
factory a  manner  as  telpherage. 

Telpherage  has  been  very  successfully  employed  as  a  means 
of  carrying  materials  from  one  part  to  another  of  large  and  exten- 
sive factories,  in  carrying  coal  and  ashes  in  power-houses,  in  con- 
vejTing  the  products  of  farms  and  plantations,  and  in  the  trans- 
portation of  ores  in  mining.  In  general,  it  may  be  said  that 
wherever  material  is  to  be  carried  to  a  distance,  there  is  no  power 
so  flexible,  so  economical  in  first  cost  of  installation,  costing  so 
little  for  power  or  the  expense  of  maintenance,  and  with  such 
great  capacity,  as  telpherage. 

Notwithstanding  the  United  Telpherage  Company  states  that 
this  method  of  transportation  of  excavated  materials  can  be  advan- 
tageously employed  in  the  construction  of  roads,  railroads,  and 
canals,  it  has  not  yet  enjoyed  the  favor  of  the  engineers  and  con- 
tractors. The  writer  has  no  knowledge  that  it  has  ever  been 
employed  on  public  works,  with  the  exception  of  an  aerialway 
provided  with  an  electric  motor  which  was  used  on  some  sections 
of  the  New  York  rapid-transit  subway.  It  was  invented  by 
Mr.  W.  F.  Brothers  of  New  York  City,  and  can  be  considered 
among  the  telpherage  systems  more  properly  than  under  cable- 


250 


EARTH    AND    ROCK    EXCAVATION. 


ways,  because  the  single  skip  is  hoisted  and  moved  back  and 
forth  along  the  cable-track  by  means  of  electric  motors  instead  of 
being  moved  by  hoisting-  and  hauling-ropes.  This  special  electric 
cableway  is  illustrated  in  Figs.  123,  124,  and  125,  and  was  de- 
scribed in  Engineering  News  as  follows: 

One  of  the  unique  features  of  this  cableway  is  the  manner  in 
which  the  main  cable  is  supported.  It  is  fixed  at  either  end  to  an 
inclined  A  frame,  which  is  free  to  swing  up  and  down,  and  is 
loaded  by  a  weight  hanging  at  its  outer  end.  The  cables  sup- 
porting the  weights  on  the  A  frames  are  of  such  a  length  that 
both  weights  cannot  rest  upon  the  ground  at  the  same  time.  The 
proper  magnitude  of  these  weights  is  known  from  the  deflection 
of  the  main  cable  when  the  latter  is  hanging  freely. 

When  the  carriage  travels  away  from  one  of  the  shears,  the 
main  cable  sags  and  the  weight  at  that  end  rises,  but  when  the 
carriage  returns  the  change  in  the  inclination  of  the  main  cable 
at  the  point  where  it  is  attached  to  the  shear  is  sufficient  to  give 
the  weight  a  preponderance,  and  it  sinks. 

This  may  be  understood  from  the  triangle  of  forces  in  Fig. 
123.  Let  AB  be  the  force  exerted  by  the  weight  hanging  verti- 


FIG.  123. 


cally;  it  is  constant  in  magnitude  and  direction.  BC  will  be 
the  tension  in  the  main  cable,  and  CA  the  thrust  in  the  A  frame. 
If  the  inclination  of  BC  now  changes  to  bC,  AB  will  be  greater 


TRANSPORTING    EXCAVATED    MATERIALS   BY   TELPHERAGE.    251 

than  the  resultant  of  bC  and  CA,  and  will  pull  the  end  of  the  A 
frame  down  until  a  new  position  of  equilibrium  is  reached,  as 
indicated  by  the  triangle  BCA.  The  work  done  by  the  falling 
weight  is  expended  in  lifting  the  load  on  the  carriage  so  that  the 
motor  is  assisted  a  certain  amount  as  it  approaches  the  A  frame. 
And  also  on  account  of  the  automatic  lowering  of  the  latter  there 
is  less  total  work  to  do.  An  important  advantage  of  this  arrange- 
ment is  that  the  skip  may  be  brought  out  beyond  the  point  of 
support  of  the  A  frame,  as  can  be  seen  in  Fig.  124.  The  machine 


FIG.  124. 

is  operated  by  electricity,  and  the  electric  motor  is  mounted  directly 
on  the  traveling  carriage.  The  operator  rides  on  the  carriage 
and  controls  the  operations  of  hoisting,  conveying,  dumping,  and 
lowering  by  a  system  of  switches.  The  electric  motor  which  per- 
forms the  work  of  hoisting  and  conveying  on  the  carriages  is  of 
15  H.P.  capacity,  and  is  provided  with  the  usual  switches,  rheo- 
stat, and  other  controlling  devices.  A  reversing-switch  enables  it 
to  drive  the  carriage  in  either  direction.  Upon  the  end  of  the 
motor-shaft  is  mounted  a  friction-pulley  which  may  be  caused 
to  engage  and  drive  either  of  the  two  large  wood-rimmed  pulleys 
to  be  seen  upon  the  farther  side  of  the  carriage  in  Fig.  125.  The 
shaft  of  the  upper  large  pulley  carries  a  pinion  which  engages 


252 


EARTH    AND    ROCK    EXCAVATION. 


with  teeth  on  the  periphery  of  the  two  traveling-  wheels.     The 
lower  wood-rimmed  pulley  operates  by  worm-gearing  the  drums 

upon  which  are  wound  the  cables 
from  which  the  skip  is  suspended. 
These  drums  may  be  worked  inde- 
pendently, and  in  that  way  the 
skip  may  be  dumped.  The  motor- 
cars hoist  and  carry  a  skip-load  of 
about  three  tons.  The  current  is 
led  to  the  motor  by  a  small  trolley- 
wire  strung  below  the  main  cable, 
and  which  may  be  seen  passing 
over  the  two  small  wheels  at  the 
side  of  the  carriage.  The  main 
cable  carries  the  return  current. 
The  main  cable  would  usually  be 
grounded,  but  in  the  installation 
of  this  system  on  the  Section  11 
of  the  New  York  rapid-transit, 
which  is  here  illustrated,  a  220-volt 
direct  current  was  taken  from  the  Edison  three-wire  system. 
This  necessitates  insulators  in  the  hoisting-ropes  leading  to  the 
skip,  which  in  the  present  instance  are  short  pieces  of  manilla 
rope. 

The  advantage  of  this  cableway  is  that  one  man  does  the 
work  which  requires  two  or  more  men  in  other  types  of  trench- 
machines.  Besides,  the  operator  is  located  close  to  the  skip 
which  is  being  moved,  and  he  can  direct  the  movements  much 
more  easily  than  when  he  is  located  some  distance  away,  as  is 
the  engineman  operating  the  common  steam  trench-machine. 
Another  advantage  is  that  the  A  frame  may  be  mounted  upon 
wheels.  If  one  is  so  mounted  and  the  other  end  of  the  cable  is 
fixed,  the  frame  may  be  made  to  travel  about  on  a  circular  track, 
having  the  center  of  curvature  at  the  fixed  support.  In  this 
way  a  large  area  may  be  covered.  In  a  similar  manner  both 
frames  may  be  mounted  upon  wheels  running  upon  parallel  tracks. 


125. 


TRANSPORTING  EXCAVATED  MATERIALS  BY  TELPHERAGE.  253 

The  work  of  this  machine  is  given  by  the  inventor  and  manu- 
facturers at  4  c.  per  cu.  yd.  of^ earth  excavated.  This  machine  could 
be  conveniently  employed  fo^ several  purposes  on  public  works. 
On  account  of  the  special  arrangement  of  the  A  frame  just  indi- 
cated, it  is  very  valuable  in  the  excavation  of  small  distributing 
reservoirs  and  of  large  canals  in  which  the  excavated  material 
has  to  be  dumped  in  some  place  alongside  its  edges.  One  of 
these  machines,  with  a  span  of  over  100  ft.,  was  used  by  Mr.  John 
Shield,  the  contractor  for  Section  11  of  the  New  York  rapid- 
transit  railway.  It  has  given  perfect  satisfaction  in  all  the 
points  claimed  by  the  inventor,  but  Mr.  Shepard,  the  engineer  for 
the  contractor,  states  that  in  the  present  form  it  is  a  little  too 
slow  for  the  handling  of  earth,  while  it  is  the  best  device  that 
could  be  adopted  in  the  construction  of  dams  where  all  the  vari- 
ous stones  could  be  set  by  the  operator  in  a  more  correct,  and 
also  in  an  easier  and  quicker  manner  than  with  any  other  means. 

Telpherage  can  be  used  also  in  excavating  and  leveling,  in 
preparing  road-beds  for  railroads,  as  it  is  shown  in  the  accompany- 
ing diagram  (Fig.  126).  In  such  a  case  the  function  of  the  telpher 


FIG.  126. 

is  to  transport  the  hoist,  bucket,  and  load.  The  hoist  does  the 
excavating  and  elevating.  The  hoist  automatically  brakes  itself 
either  upon  the  girder-rail  or  grips  the  cable  as  soon  as  there  is 
any  longitudinal  strain. 

Although  the  excavation  can  doubtless  be  done  by  means  of 


254  EARTH  AND  ROCK  EXCAVATION. 

telphers,  the  writer  does  not  know  of  any  instance  in  which  tel- 
phers have  been  employed  for  such  a  purpose;  while,  on  the 
other  hand,  movable  cableways  have  been  used  with  splendid 
results.  Thus  on  Section  9  of  the  Chicago  Drainage  Canal  the 
excavation  of  the  surface  material  was  made  by  a  large  scraper 
commanded  by  movable  cableway,  which  was  designed  and 
patented  by  Charles  Vivian  and  controlled  by  the  Lidgerwood 
Manufacturing  Company.  It  was  adapted  to  deal  with  soft  material, 
which  it  did  very  efficiently,  and  has  been  successfully  employed 
since  for  handling  sand  and  gravel  in  the  excavation  of  canals  and 
for  railroad  work  where  a  deep  cut  and  fill  adjoin  each  other. 

The  Vivian  scraper  is  made  of  steel  5X5X2J  ft.  and  having 
a  capacity  of  about  3  cu.  yds.  It  is  filled,  conveyed,  and  dumped 
by  means  of  ropes  moved  by  an  engine  located  at  the  rear  of  the 
spoil-bank.  The  ropes  are  supported  by  two  high  wooden  towers 
provided  with  sheaves  and  head-tackle.  The  engine  and  boiler 
as  well  as  both  towers  are  mounted  on  cars  in  order  to  follow  the 
work. 

The  Vivian  scraper  is  operated  in  the  following  way:  The 
endless  running-rope  of  the  cableway  attached  to  the  rear  of  the 
scraper  is  pulled  until  the  scraper  stands  at  an  angle  of  about  45° 
with  the  ground.  The  drag-rope  connected  to  the  other  drum 
of  the  engine  is  then  put  into  gear,  and  the  scraper  will  be  pulled 
along.  The  endless  rope  is  controlled  by  the  brake  until  the 
scraper  is  filled,  then  the  endless  rope  is  slacked  off  and  the  scraper 
hauled  to  the  spoil-bank  by  the  drag-rope.  To  dump  the  scraper, 
the  drag-rope  is  thrown  out  of  gear  and  the  endless  rope  into  gear, 
upsetting  the  scraper,  which  will  unload  its  contents.  When 
emptied  the  engine  is  reversed  and  the  endless  rope  will  return 
the  scraper  to  the  cut,  allowing  the  drag-rope  to  overhaul.  The 
Vivian  scraper  is  operated  by  three  ropes — one  IJ-in.  drag-cable 
which  drags  the  loaded  scraper,  and  two  f-in.  ropes,  one  of  which 
dumps  the  scraper  on  the  spoil-bank,  while  the  other,  called  the 
out-haul  rope,  returns  the  scraper  for  another  load.  These  two 
latter  ropes  wind  on  the  opposite  side  of  the  same  drum. 

Fig.  127  shows  the  Vivian  scraper  loaded  and  dragged  toward 


TRANSPORTING    EXCAVATED    MATERIALS    BY   TELPHERAGE.     255 

the  spoil-bank,  and  Fig.  128  ghows  the  tail-tower  of  the  scraper 
as  it  was  used  at  Massena,  A.  Y.,  by  the  T.  A.  Gillespie  Company, 
Contractors,  for  the  carnal  of  tne  St.  Lawrence  Power  Company.  In 


Vivian  Scraper  .- 
FIG.   127. 


the  Chicago  Canal  500  cu.  yds.  of  earth  were  often  removed  in  a  day, 
but  the  quantity  of  the  excavated  material  chiefly  depends  upon 
the  quality  of  the  soil  and  the  dimensions  of  the  scrapers.  Thus 
at  Massena  a  greater  efficiency  was  obtained  from  a  scraper  7  X  7  ft. 
But  it  will  be  safer  to  calculate  at  500  cu.  yds.  per  ten-hour  day's 


Scraper 
FIG.   128. 

work  the  quantity  of  loose  soil  excavated  and  deposited  on  the 
spoil-bank  by  means  of  the  Vivian  scraper  operated  by  a  movable 
cableway.  The  daily  running  expenses  for  excavating  and  haul- 
ing earth  by  means  of  the  Vivian  scraper  are  given  by  the  daily 
consumption  of  coal  and  the  required  labor.  This  consists  of  a 
crew  composed  of  1  engineer,  1  fireman,  and  2  signalmen. 


CHAPTER  XVIII. 

CHAINS,  ROPES,  BUCKETS,  ENGINES,  AND  MOTIVE  POWER. 

IN  concluding  the  description  of  the  various  machines  used 
for  excavating  and  hauling  it  is  desirable  to  devote  a  few  words 
to  ropes,  buckets,  hoisting-engines,  and  motive  power,  which 
have  already  been  mentioned  on  several  occasions. 

In  the  steam-shovel  and  crane  the  hoisting  is  usually  done 
by  means  of  chains.  These  are  formed  of  several  links  inserted 
into  one  another  at  right  angles.  Each  link  is  made  of  an  iron 
rod  with  a  diameter  varying  with  the  work  expected  from  the 
chain,  but  generally  from  J  in.  to  3  ins.  They  are  bent  and  welded 
into  the  form  indicated  in  Fig.  129.  Chains  have  the  defect  of 
wearing  off  very  easily,  and  this  is  due  to  the  great  friction  to 
which  they  are  subjected  in  passing  over  the  sheaves  and  drums; 
they  become  weaker  and  weaker  until  they  are  condemned  or 
break.  Chains  require  to  be  lubricated  continuously. 

Lately  the  C.  W.  Hunt  Company  of  New  York  have  introduced 
onto  the  market  a  laminated  chain  (Fig.  130)  which  is  notable 
for  strength,  economy,  durability,  and  smoothness  of  action. 
The  links  in  this  chain  are  flat,  are  punched  from  steel  especially 
rolled,  and  are  connected  together  by  means  of  rivets.  By  its 
special  construction  the  chain  affords  a  great  resistance  to  wear 
and  'oJ',  and  is  articulated  so  that  it  can  easily  be  wound  around 
drums.  They,  however,  cannot  be  wound  on  a  parallel  drum, 
but  must  be  wound  in  a  spiral.  Engines  are  constructed  with 
drums  wide  enough  to  wind  the  laminated  chains  in  a  single  coil. 
The  advantages  of  this  chain  are  that  there  is  no  danger  of  break- 
ing without  warning,  that  they  are  more  economical  both  in 
maintenance  and  repairs,  and  that  any  man  in  a  half  hour's  time 

256 


CHAINS,  ROPES,  BUCKETS,  ENGINES,  AND   MOTIVE    POWER.    257 

3. 

can  lengthen  or  shorten  the  chain  or  remove  any  part  and  insert 
a  new  piece  in  its  place.     If  an  examination  of  the  chain  is  wanted, 


a  rivet-head  is  cut  off  and  the  chain  taken  apart.    A  new  rivet 
will  immediately  make  the  chain  good  again. 

In  the  last  twenty  years  ropes  have  acquired  a  great  importance 
in  engineering  and  mechanical  works,  both  for  hauling  purposes 


258  EARTH  AND  ROCK  EXCAVATION. 

and  for  transmission  of  power.     They  are  usually  manufactured 
from  two  materials — steel  or  iron  wires  and  Manilla  fiber. 

Manilla  rope  is  made  from  the  fiber  of  the  Aloe  plant,  which 
grows  only  in  the  Philippine  Islands.  The  trunk  of  this  plant, 
which  resembles  the  banana-tree,  is  closely  enfolded  by  long  leaves, 
and  from  these  leaves  is  procured  the  fiber  so  wonderfully  suited 
to  the  requirements  of  rope-making.  This  fiber  varies  in  length 
from  6  to  12  ft.,  and  in  some  leaves  attains  a  length  of  18  ft.  Its 
tensile  strength  is  remarkable;  official  tests  at  Water  town,  Mass., 
have  proved  it  to  be  in  excess  of  50,000  Ibs.  per  sq.  in.  This 
great  strength,  however,  is  shown  only  when  the  fibers  are  sub- 
jected to  a  longitudinal  strain.  Transversely,  owing  to  their 
cellular  formation,  the  fibers  are  relatively  weak.  Transmission 
rope  is  made  with  three,  four,  or  six  strands;  the  last  two  have 
an  inner  core,  or  heart,  around  which  the  outer  strands  are  laid. 
Manilla  ropes  are  used  extensively  for  the  transmission  of  power 
as  substitute  for  the  leather  belts,  and  their  description  has  been 
taken  from  the  Httle  book  on  rope  transmission  published  by  the 
American  Manufacturing  Company,  of  New  York.  Although 
Manilla  ropes  are  very  useful  to  the  contractors,  yet  in  connection 
with  excavating  and  hauling  apparatus  only  wire  ropes  are  used. 

Wire  rope  is  made  of  wires  either  twisted  together  or  laid 
parallel  to  each  other.  The  latter  kind  is  employed  only  in  large 
suspension  bridges,  while  the  former  is  in  general  use.  There  are 
two  forms  of  wire  ropes,  flat  and  round.  Flat-wire  ropes  consist 
of  a  number  of  wire  strands  which  have  been  laid  side  by  side 
and  sewed  together  with  annealed  wire.  Round  ropes,  which 
are  the  most  commonly  employed,  are  composed  of  a  number  of 
wire  strands  twisted  around  a  core  of  hemp  or  around  a  wire 
strand  or  wire  rope.  The  standard  wire  rope  is  made  of  six  wire 
strands  and  a  hemp  core;  this  arrangement  affords  the  most  con- 
venient and  compact  form,  as  the  strands  and  the  core  are  prac- 
tically all  of  the  same  size.  The  core  of  a  wire  rope  is,  as  a  rule, 
hemp  saturated  with  tar.  It  provides  little  additional  strength, 
but  acts  as  a  cushion  to  preserve  the  shape  of  the  rope  and  helps 
to  lubricate  the  wires.  Wire  strands  are  made  of  wires  twisted 


CHAINS,  ROPES,  BUCKETS,  ENGINES,  AND    MOTIVE    POWER.    259 


together.  The  number  of  w%es  commonly  used  are  four,  seven, 
twelve,  nineteen,  and  thirty-seven,  depending  upon  the  nature  of 
the  work  for  which  the  strands  are  intended.  Ordinarily  the 
wires  are  twisted  in  the  opposite  direction  to  the  twist  of  the 
strands  in  the  rope. 

The  strength  of  wire  ropes  depends  chiefly  upon  the  material 
of  which  the  wires  are  made.  As  a  rule  it  can  be  assumed  that 
it  is  only  80  per  cent,  of  the  aggregate  strength  of  all  of  its  wires. 
Thus  the  strength  of  the  iron  wires  ranges  from  45,000  to  100,000 
Ibs.  per  sq.  in. ;  open-hearth  steel  from  50,000  to  130,000  Ibs.  per 
sq.  in. ;  crucible  steel  from  130,000  to  190,000  Ibs.  per  sq.  in. ;  and 
plow  steel  from  190,000  to  350,000  Ibs.  per  sq.  in.  The  working 
load  is  usually  calculated  at  one-seventh  of  the  strength  of  the 
wire  rope.  This  factor  of  safety,  however,  should  be  modified  for 
special  cases;  thus,  for  instance,  elevator  ropes  seldom  have  a 
load  of  more  than  one-tenth  or  one-fifteenth  of  their  breaking 
strain. 

The  following  table  taken  from  the  catalogue  of  the  American 
Hoist  &  Derrick  Co.  gives  the  tensile  and  working  strength  of 
various  ropes : 

STANDARD    STEEL    HOISTING-ROPES. 

Six  strands.     Nineteen  wires  per  strand.     Hemp  center. 


Crucible  -steel  Quality. 

Plow-steel  Quality. 

Weight 
100  Feet. 

Breaking 
Strain  in 
Tons  of 

Proper  Work- 
ing Load 
in  Tons  of 

Diameter. 

Proper  Work- 
ing Load 
in  Tons  of 

Breaking 
Strain  in 
Tons  of 

Weight 
100  Feet. 

2000  Lbs. 

2000  Lbs. 

2000  Lbs. 

2000  Lbs. 

26 

4| 

i 

t 

1J 

8 

26 

35 

7i 

i 

2| 

12 

35 

63 

14 

2 

A 

34 

20 

63 

88 

18 

3 

| 

5 

27 

88 

120 

25 

5 

£ 

7 

37 

120 

158 

33 

6 

9 

50 

158 

200 

42 

8 

I| 

12 

63 

200 

250 

52 

10 

H 

15 

76 

250 

But  wire  ropes  are  not  always  used  to  hoist  the  materials  hi  a 
vertical  direction;  they  may  be  employed  for  hauling  materials 
on  inclined  planes.  Messrs.  A.  Roebling  &  Son  give  the  following 
table  in  which  the  strain  produced  by  any  load  can  easily  be 


260 


EARTH    AND    ROCK    EXCAVATION. 


calculated.  It  gives  the  strain  on  a  rope  due  to  a  load  of  one  ton 
of  2000  Ibs.  allowing  for  rolling  friction.  An  additional  allowance 
for  the  weight  of  the  rope  will  have  to  be  made. 


Elevation 
in  100  Feet. 

Corresponding 
Angle  of  Incli- 
nation. 

Strain  in 
Pounds  on  Rope 
from  a  Load  of 
2000  Pounds. 

Elevation 
in  100  Feet. 

Corresponding 
Angle  of  Incli- 
nation. 

Strain  in 
Pounds  on  Rope 
from  a  Load  of 
2000  Pounds. 

5 

24° 

112 

95 

43  i° 

1385 

10 

5i° 

211 

100 

45° 

1419 

15 

8^° 

308 

105 

46  £° 

1457 

20 

HT*° 

404 

110 

47f° 

1487 

25 

14iV° 

497 

115 

49° 

1516 

30 

16f° 

586 

120 

50i° 

1544 

35 

19§° 

673 

125 

51  i° 

1570 

40 

2lji0 

754 

130 

52  i° 

1592 

45 

241° 

832 

135 

53  A° 

1614 

50 

26|° 

905 

140 

54  1° 

1633 

55 

28|° 

975 

145 

55  J° 

1653 

60 

31° 

1040 

150 

561° 

1671 

65 

70 

33^° 
35° 

1100 
1156 

155 
160 

58° 

1689 
1703 

75 

37° 

1210 

165 

58f° 

1717 

80 

38§° 

1260 

170 

59J 

1729 

85 

40  J° 

1304 

175 

1742 

90 

42° 

1347 

In  the  preceding  chapters  it  has  been  seen  that  wire  ropes 
are  used  in  public  works  chiefly  for  two  different  purposes,  either 
for  hoisting  or  as  tracks  for  the  aerialways.  When  used  for  the 
latter  purpose,  they  have  the  same  construction  as  when  em- 
ployed in  hoisting,  except  that  the  strands  contain  more  wire 
and  the  diameter  of  the  rope  is  usually  greater  than  1  in.  There 
is  no  doubt  that  these  wire-rope  trackways  are  liable  to  wear  off 
very  easily,  and  when  the  outside  wires  are  worn  out,  the  rope 
becomes  useless  and  must  be  discarded.  Besides,  the  twisted 
wire  composing  the  strands  form  an  irregular  surface  which  results 
in  wear  and  a  great  waste  of  force  in  hauling. 

To  avoid  these  objections  a  track-cable  of  special  construction 
has  been  invented  and  patented.  It  is  known  on  the  market  as 
the  "  patent  locked-coil  cable,"  and  it  was  so  called  from  the  fact 
that  the  outer  wires  are  of  such  shape  that  they  interlock  with 


CHAINS,  ROPES,  BUCKETS^  ENGINES,  AND   MOTIVE    POWER.    261 

I 

each  other,  as  shown^in  Fig.  *31.  They  present  a  smooth  surface 
and  yet  possess  sufficient  flexibility  to  be  shipped  in 
coils.  With  this  cable  are  obviated  the  difficulties 
resulting  from  fractured  wires  and  uneven  surfaces, 
while  the  wearing  of  the  carriage-wheels  will  be  a 
minimum.  This  cable  is  made  of  steel  in  lengths  of 
from  800  to  1200  ft.,  which  are  joined  by  patent 
couplings.  They  have  been  especially  constructed  to 
be  used  as  trackways  in  connection  with  the  Bleickert 
cableway,  controlled  in  this  country  by  the  Trenton 
Iron  Company.  The  track-cables  are  graduated  to 
the  loads  and  pressure  they  have  to  sustain,  and, 
being  stationary,  possess  the  great  advantage  of  re- 
lieving the  traction-rope  of  the  weight  of  the  loads, 
so  that  on  comparatively  level  lines  the  tension  upon 
the  traction-rope  is  but  little  more  than  the  tractive 
force  required  to  move  the  loads.  FlG- 131- 

The  author  has  found  that  these  ropes  are  more  expensive  in 
first  cost,  and  also  very  expensive,  owing  to  the  fact  that  the 
whole  rope  becomes  entirely  useless  when  only  one  of  the  inter- 
locked wires  gets  out  of  place.  It  is  true,  however,  that  on  account 
of  the  smooth  surface  smaller  force  is  required  for  hauling  the 
carriage,  and  both  the  truck  of  the  carriage  and  the  rope  itself 
are  subjected  to  less  wear. 

The  manufacturers  claim  that  laminated  chains  never  wear 
out  in  the  ordinary  sense  of  the  term.  The  wear  is  greater  on  the 
working  end  of  the  chain  than  on  the  drum  end.  A  piece  5  or 
10  ft.  long  is  cut  off  on  the  working  end  when  it  shows  wear,  and 
a  corresponding  length  of  new  chain  is  riveted  to  the  drum  end. 
Thus  the  chain  advances  forward  step  by  step,  the  engine  end 
being  always  new  and  the  working  end  the  most  worn  part.  The 
advantage  from  this  facility  of  repair  or  renewal  of  a  worn  part 
by  the  engineer  in  charge,  together  with  the  great  durability  in 
service,  makes  the  expense  of  laminated  chain  per  ton  of  material 
hoisted  a  sum  insignificant  when  compared  with  steel-wire  rope 
that  must  be  wholly  thrown  away  if  one  part  is  worn  too  much 


262 


EARTH    AND    ROCK    EXCAVATION. 


for  safe  hoisting.  Laminated  chains  are  built  in  three  different 
sizes,  and  their  breaking  strength  and  their  equivalent  strength 
as  compared  with  wire  ropes  are  given  in  the  following  table: 


Equivalent  in  Strength  to 

Patent  Lami- 
nated Chain. 

Breaking 
Strength, 
Actual  Test. 

Iron-  wire  Rope. 

Crucible-steel 
Wire  Rope. 

Crane  Chain. 

No.  835 

36,000 

1  inch 

|  inch 

$  inch 

"     845 

46,000 

11  '  ' 

i"    '  ' 

1     " 

"    860 

62,000 

If" 

1     " 

1  1       .  . 

Skips. — The  materials  which  are  raised  from  the  bottom  to 
the  top  of  the  excavation  by  means  of  hoisting-  and  conveying- 
machines  are  placed  in  receptacles  or  skips  of  different  forms, 
varying  with  the  quality  of  the  material  removed  and  the  special 
conditions  of  the  work.  The  most  commonly  employed  recep- 
tacles are  scales  and  buckets  for  earth,  and  grabbing-chains  for 
stones. 

Scales. — Scales  are  usually  made  of  wood  reinforced  with  iron. 
They  consist  of  a  square  platform  3  ft.,  sides  surrounded  by  boards 
H  ft.  high  on  three  sides.  Attached  to  the  platform  and  in  the 
center  of  the  open  side  of  the  scale  there  is  an  iron  ring,  and  two 
similar  rings  are  provided  at  the  top  of  the  rear  end  of  the  two 
parallel  side-boards.  The  scale  is  lifted  by  placing  in  these  rings 
hooks  attached  to  the  end  of  a  system  of  three  short  chains,  which 
are  suspended  to  the  hoisting-block.  On  account  of  this  arrange- 
ment, in  hoisting  the  scale  the  material  that  it  contains  will  gravi- 
tate toward  the  interior,  thus  preventing  it  from  spilling  from 
the  open  side.  The  unloading  of  these  scales  is  very  simple. 
When  the  dumping-place  has  been  reached,  which  may  be  either 
a  wagon,  a  car,  a  bin,  or  the  spoil-bank,  the  scale  is  lowered  so  as 
to  relieve  the  chains  of  the  weight,  then  the  front  chain  is  re- 
moved from  the  ring  and  the  scale  is  slowly  hoisted.  Being 
then  attached  only  by  the  rear  rings  this  part  will  be  raised  while 
the  front  will  continue  to  remain  at  rest,  and  consequently  the 
material  will  rush  to  this  side  and  the  scale  will  empty  its  contents 
into  the  required  place. 


CHAINS,  ROPES,  BUCKETS,  ENGINES,  AND   MOTIVE   POWER.    263 

Ik 

Scales  are  subjected  td  a  great  deal  of  wear  and,  especially 
when  handling  rocks,,  they  *fre  easily  destroyed.  In  such  a  case 
it  is  more  convenient  to  have  them  made  of  steel,  like  those  used 
in  the  construction  of  the  tunnels  under  Park  Avenue  for  the  New 
York  rapid-transit  railroad.  Here  the  scales  employed  were 
4X4X2  ft.,  and  were  made  of  steel  and  reinforced  pieces  of  iron. 
The  scales  were  placed  on  top  of  platform  cars  and  loaded  with 
the  material  at  the  front  of  the  excavation,  and  hauled  to  the 
bottom  of  the  shaft  from  which  they  were  raised  to  the  surface 
by  means  of  stiff-leg  derricks,  and  the  material  they  contained  was 
dumped  into  specially  constructed  bins. 

Scales  can  also  be  automatically  dumped  in  the  air,  as  is  clearly 
shown  in  the  reproduction  (Fig.  118),  from  an  instantaneous 
photograph.  This  manner  of  dumping  was  employed  in  the 
excavation  of  the  Chicago  Drainage  Canal,  and  the  scales  were 
attached  to  the  hoisting-rope  of  the  hoisting  and  conveying  cable- 
ways  stretched  across  the  canal  and  over  the  spoil-banks,  which 
were  located  at  one  side  of  the  canal.  The  aerial  dump  of  the 
scale  was  obtained  by  means  of  an  auxiliary  rope,  running  from 
the  hoisting-drum  of  the  engine  over  the  carriage,  and  attached 
to  the  third  chain  of  the  skip.  As  the  carriage  approached  the 
head-tower  and  the  scale  was  just  above  the  spoil-bank,  this 
auxiliary  rope  was  drawn  in  at  a  higher  rate  of  speed,  thus  raising 
the  end  of  the  scale  and  spilling  the  load  at  the  will  of  the  engineer 
and  while  the  carriage  was  in  motion.  The  engine  was  then  in- 
stantly reversed,  and  the  carriage  went  back  over  the  canal,  the 
empty  scale  which  had  resumed  its  horizontal  position  was  low- 
ered and  unfastened,  and  the  chains  hooked  to  a  full  scale. 

•  Buckets. — In  connection  with  cableways,  especially  for  hand- 
ling stone  and  other  material  in  sewer  and  general  construc- 
tion work,  steel  tipping-buckets  are  commonly  employed  instead 
of  scales.  These  are  of  the  form  indicated  in  Fig.  132.  The  body 
of  the  bucket  is  made  of  steel  sheet  reinforced  at  the  edges;  and 
the  bottom  is  narrower  than  the  top,  so  that  its  longitudinal  cross- 
section  is  in  the  form  of  a  trapezium,  with  the  longest  of  its  parallel 
sides  on  top.  A  heavy  steel  handle  in  the  form  of  an  inverted  U 


264  EARTH  AND  ROCK  EXCAVATION. 

is  bolted  to  the  body  of  the  skip  in  such  a  manner  that  the  skip 
can  revolve  around  these  points  of  support.  They  are  so  bal- 
anced that  they  are  top-heavy  when  full,  and  bottom-heavy  when 
empty,  consequently  they  are  self-dumping  and  self-righting.  To 
prevent  their  overturning  when  loaded,  there  is  a  spring-latch  on 
the  outside  of  the  bucket,  which  is  opened  by  a  man  when  the 


bucket  has  been  brought  up  to  the  point  of  dumping.  The  material 
then  descends  along  the  inclined  side  of  the  bucket  as  in  a  chute, 
and  once  liberated  of  the  load  the  bucket  raises  automatically  and 
the  latch  catches  into  position  again. 

The  following  table,  taken  from  the  catalogue  of  G.  L.  Stuebner, 
gives  the  dimensions  of  the  various  steel  buckets  manufactured. 
Of  these,  however,  only  those  marked  125,  127,  129,  130,  and  131 
are  usually  employed  in  excavations  for  hoisting  materials. 

From  this  table  it  is  seen  that  with  buckets  of  1  cu.  yd.  capac- 
ity, which  are  those  most  commonly  employed  in  earthworks,  the 
height  of  the  bucket  is  about  30  ins.,  and  consequently  the  shoveler 
must  make  a  greater  effort  in  loading  a  bucket  than  a  scale,  since 
every  shovelful  must  be  raised  at  least  over  30  ins.  instead  of  only 


CHAINS,  ROPES,   BUCKETS,  ENGINES,  AND   MOTIVE    POWER.    265 


TABLE  OF  SIZEJ^OF  TIPPING-BUCKETS. 


Size  No.  of 
Bucket. 

Capacity  in 
Cubic  Feet. 

Length  of  Bucket 
in  Inches. 

Width  over  all 
in  Inches. 

Depth 
in  Inches. 

123 

6 

33 

26 

19 

124 

8 

36 

27 

22 

125 

10 

41 

30 

24 

126 

12 

42 

33 

25 

127 

14 

48 

33 

27 

128 

18 

48 

37 

29 

129 

21 

48 

43 

30 

130 

27 

46 

46 

31 

131 

27 

53 

43 

29 

132 

36 

58 

54 

33 

132 

42 

60 

58 

33 

18  ins.,  as  in  the  scale.  Now,  since  the  work-of  men  is  limited  to  a 
certain  number  of  foot-pounds  per  day,  the  smaller  the  effort  re- 
quired to  raise  the  material  for  loading  the  skips  the  greater  will  be 
the  efficiency  of  the  work.  From  this  point  of  view  scales  should 
always  be  preferred  to  the  buckets  when  no  other  circumstances 
require  the  employment  of  the  latter.  Buckets,  however,  are 
more  lasting  and  easily  handled  by  the  men  than  scales  and  for 
this  reason  they  are  preferred. 

Grabbing-hooks.  —  It  is  too  expensive  to  break  into  small 
fragments  the  large  stones  detached  from  the  bank  by  blasting, 
so  that  they  may  be  placed  either  in  scales  or  buckets.  It  is  more 
convenient  to  raise  these  large  stones  to  the  surface  without  break- 
ing them,  and  this  is  accomplished  by  means  of  grabbing-hooks. 
These  consist  of  two  steel  hooks  of  the  form  indicated  in  Fig.  133. 
Each  hook  is  provided  with  a  ring  so  that  it  may  slide  on  a  chain 
made  with  short  links.  The  chain  is  attached  to  the  hoisting- 
rope  of  a  derrick  or  cableway,  and  is  lowered  to  the  place  where 
the  large  stone  stands,  then  the  laborers  place  the  hooks  one  oppo- 
site the  other  and  in  such  a  way  as  to  grab  the  projecting  parts 
of  the  stone.  The  hoisting-rope  is  drawn  up  and  the  chain  pulls 
the  hooks  together,  so  that  they  firmly  hold  the  stone  which  will 
be  brought  up  to  the  surface  and  removed  to  the  required  place. 
To  detach  the  hooks,  the  hoisting-rope  is  lowered  until  they  are 
released. 


266  EARTH  AND  ROCK  EXCAVATION. 

Hoisting-engines  have  already  been  mentioned  several  times 
in  the  preceding  chapters.  These  are  constructed  with  drums 
running  in  either  direction,  and  are  called  reversible  engines. 
They  can  be  operated  by  a  single  cylinder  or  two  cylinders,  and 


are  then  known  either  as  single-  or  double-cylinder  reversible 
engines. 

The  single-drum  reversible  engine,  either  with  a  single  or 
double  cylinder,  is  used  in  connection  with  cableways  of  the  Otto, 
Blieckert,  and  similar  systems,  and  also  for  mining  purposes,  but 
very  seldom  in  public  works.  Double-drum  reversible  engines 
are  very  commonly  employed  in  engineering  works  to  operate 
derricks  and  cableways.  Three-drum  reversible  engines  are  now 
constructed  to  operate  derricks  provided  with  bull-wheels  for 
slewing  the  boom.  Since  the  single-drum  reversible  engine,  as 
well  as  the  one  with  three  drums,  is  not  common,  only  the 
double-drum  double-cylinder  reversible  hoisting-engine  will  be 
illustrated  here. 

Engines  can  be  operated  either  by  steam  or  by  compressed 
air.  They  are  now  constructed  also  so  as  to  be  operated  by  elec- 


CHAINS,  ROPES,  BUCKETS,  ENGINES,  AND    MOTIVE   POWER.    267 


tricity.  Since  their  construction  is  somewhat  different  from  the 
ordinary  hoisting-engines,  it  seems  desirable  to  give  a  description 
of  a  double-drum  reversible  hoisting-engine. 

Double-drum  Reversible  Engine. — The  engine  is  mounted  on 
a  cast-iron  bed-plate  which  has  two  standards  for  the  support  of 
the  drum.  They  can  be  either  cast  together  with  the  frame,  or 
securely  bolted  to  the  frame,  and  their  alignment  is  preserved  by 
pins.  The  cylinder,  or  cylinders,  since  the  great  majority  of 
hoisting-engines  are  provided  with  two  cylinders,  are  located 
horizontally  and  very  close  to  the  rear  of  the  bed-plate.  They 
are  made  of  charcoal-iron  and  are  provided  with  slide-valves  of 
the  D  type.  They  are  lagged  with  wood  to  prevent  condensation, 
and  are  covered  by  a  heavy  metal  jacket.  The  piston  is  of  the 
usual  locomotive  type,  is  cast  hollow,  and  is  fitted  with  spring 
packing-rings  which  are  of  hard  cast  iron  made  up  of  different 
pieces  and  so  arranged  as  to  prevent  leaking;  the  spring  of  the 
ring  insures  a  tight  piston.  The  valve  is  of  the  standard  D  shape, 
having  a  good  bearing  surface  on  the  bottom  edge  to  prevent  wear. 
The  piston-rods,  valve-rods,  and  connecting-rods  are  of  steel.  The 
connecting-rods  are  correctly  proportioned  in  accordance  with  the 
cylinder.  They  have  square  ends  with  straps,  and  are  fitted  with 
composition  boxes  of  the  best  metal. 

The  cranks  are  forced  onto  the  shaft  by  hydraulic  pressure 
and  are  securely  keyed  with  crank-pins  exactly  at  right  angles. 
The  crank-pins  are  of  steel,  forced  into  the  cranks  by  hydraulic 
pressure  and  riveted  into  place.  Opposite  the  crank-pins  there  is 
extra  metal  so  as  to  counterbalance  the  engine  when  running  at 
high  speed.  The  winch-heads  are  of  cast  iron  and  designed  so  as 
to  give  the  best  results  as  to  holding,  hoisting,  etc.  The  foot- 
brakes  are  of  the  band  type,  lined  with  blocks  of  wood,  which 
are  fastened  to  the  band  by  means  of  lag-screws.  They  are  of 
two  forms.  In  one  the  band  is  made  in  two  pieces,  and  joined 
by  a  bolt  secured  by  jam-nuts,  by  which  means  the  wear  is  easily 
and  quickly  taken  up.  In  the  other  form  the  band  is  in  one 
piece,  the  adjustment  for  wear  being  attained  by  welding  a  piece 
of  round  iron  on  one  end  of  the  band,  cutting  a  thread  in  the  same, 


268  EARTH  AND  ROCK  EXCAVATION. 

and  passing  it  through  a  trunnion  on  the  brake-shaft  disk,  a  jam- 
nut  being  used  to  shorten  or  lengthen  the  band  as  required.  In 
both  forms  the  brake-band  is  held  clear  of  the  drum-flange  by 
means  of  a  lug  attached  to  the  fixed  band  or  guard  over  gear- 
wheels. The  foot-brake  is  counterbalanced  by  a  movable  weight ; 
they  are  very  powerful  and  very  easy  to  operate,  as,  once  being 
applied,  the  action  of  the  load  tends  to  lighten  the  brake.  They 
will  easily  hold  any  load  the  engines  are  capable  of  hoisting.  The 
guard-bands  are  of  wrought  iron  and  are  fixed  over  the  gear-wheels 
in  all  engines  to  prevent  the  rope  or  any  obstruction  from  getting 
in  the  teeth  of  the  gear. 

Fig.    134  represents   a   double-cylinder   double   friction-drum 
hoisting-engine  without  boiler  as  built  by  the  Lidgerwood  Manu- 


FIG.  134. 

facturing  Company.  It  is  specially  adapted  for  contractors, 
bridge-builders,  railroad  pile-drivers,  quarries,  and  small  suspension 
cableways.  It  is  not  a  machine  to  be  run  at  a  very  high  speed, 
but  in  places  where  economy  in  first  cost  is  a  necessity  the  engine 
answers  excellently,  works  well,  and  gives  entire  satisfaction. 
They  are  built  of  different  sizes,  as  indicated  in  the  following  table. 
In  the  last  few  years  electricity  has  been  introduced  in  many 
cases  as  a  motive  power  for  mining  and  public  works,  and  electric 
engines  have  been  devised  both  for  hauling  and  hoisting  purposes. 
Fig.  135  illustrates  an  electric  double-drum  reversible  engine 
built  by  the  Lidgerwood  Manufacturing  Company  of  New  York. 


CHAINS,  ROPES,  BUCKETS,  ^ENGINES,  AND   MOTIVE   POWER.   269 


i 

Size 
Num- 
ber of 
Engine. 

Horse- 
power 
Usually 
Rated. 

Dimensions  of 
Cylinders. 

Dimensions  of 
Hoisting-drum. 

Weight 
Hoisted 
Single 
Rope, 
Aver- 
age 
Speed. 

Suit- 
able 
Weight 
of  Pile- 
driving 
Ham- 
mer for 
Quick 
Work. 

Size  of  Bed- 
plate. 

Esti- 
mated 
Ship- 
ping 
Weight, 
Lbs. 

Diam- 
eter, 
Inches. 

Stroke, 
Inches. 

Diam- 
eter, 
Inches. 

Length, 
Inches. 

Width, 
Inches. 

Length, 
Inches. 

70| 

12 

6i 

8 

14 

16 

2,500 

2,000 

39 

76 

4,400 

71* 

20 

7 

10 

14 

18 

5,000 

3,500 

44 

88 

5,525 

72£ 

30 

8} 

10 

14 

20 

8,000 

6,000 

47 

88 

5,875 

73i 

40 

8* 

12 

16 

24 

10,000 

8,000 

62 

107 

11,500 

74* 

50 

10 

12 

16 

24 

12,000 

10,000 

62 

107 

12.000 

In  general  appearance  and  details  it  closely  resembles  the  ordinary 
steam  hoisting-engine,  with  the  difference  that  the  cylinders  are 
suppressed.  The  motive  power  is  applied  directly  to  a  shaft  by 
means  of  cog-wheels  engaging  those  on  the  motor.  This  shaft  in 
its  turn  engages  the  cog-wheels  of  the  drums,  thus  causing  their 
rotation. 

The  motor  is  of  the  armored  type  made  by  the  General  Elec- 
tric Company,  and  is  strong,  simple,  efficient,  and  compact.  All  the 
movable  parts  are  protected  by  suitable  casings,  so  that  they  are. 
not  liable  to  injury  from  dust  or  moisture,  which  renders  it  espe- 
cially adapted  for  hoisting  purposes.  The  gearing  from  the 


FIG.  135. 

motor  to  the  intermediate  shaft  is  cut,  and  is  enclosed  in  an  oil- 
tight  gear-case.  The  drum-gearing  is  cast  very  accurately;  it  is 
smooth  and  runs  well.  It  is  protected  by  the  ordinary  guard- 
band.  The  controller  is  of  the  railway  type,  and  is  mounted  so 


270 


EARTH   AND    ROCK   EXCAVATION. 


as  to  be  convenient  for  the  operator.  Each  controller  is  pro- 
vided with  a  reversing  switch,  which  can  be  used  at  will.  The 
friction-  and  brake-levers  are  mounted  in  a  rack  with  notched 
quadrant  and  are  fitted  with  thumb-latches.  The  resistance 
boxes  are  of  special  form  and  are  securely  packed  on  the  inside 
of  bed-plate,  so  that  the  hoist  is  self-contained  and  perfectly 
portable.  These  electric  hoisting-machines  are  designed  for  use 
with  a  direct  current  of  500  or  250  volts.  The  following  table 
gives  the  sizes  of  the  motor  as  built  by  the  Lidgerwood  Manufac- 
turing Company,  and  these  various  sizes  apply  to  either  voltage. 


Size  of  Drums. 

Hoisting  Duty. 

Revolu- 

Esti- 

Number 
of 
Hoist. 

Motor 
Horse- 
power. 

Style  of 
Motor. 

tions  of 
Motor, 
500 
Volts. 

mated 
Shipping 
Weight, 
Lbs. 

Diam- 
eter, 
Inches. 

Face, 
Inches. 

Weight 
Hoisted, 
Lbs. 

Speed  in 
Feet  per 
Minute. 

516 

10 

L.  W.  P.  5 

12 

16 

2000 

150 

650 

4,150 

517 

15 

G.  E.  800 

14 

20 

2500 

175 

460 

6,700 

518 

25 

G.  E.  800 

14 

22 

3500 

175 

575 

7,100 

519 

35 

G.  E.  1000 

16 

24 

5000 

200 

500 

9,200 

520 

50 

G.  E.  1200 

16 

28 

7000 

200 

550 

12,825 

The  various  motive  powers  used  in  connection  with  the  work 
of  excavation  are  steam,  compressed  air,  and  electricity.  As  a 
rule  steam  is  generally  used  for  hauling,  hoisting,  and  excavating 
purposes;  compressed  air  is  employed  for  driving  the  machines 
in  the  excavation  of  rock  and  in  hoisting;  while  electricity  may 
be  used  for  all  of  these  purposes. 

In  opening  trenches  for  the  construction  of  roads,  when  rock 
is  encountered  it  is  generally  excavated  by  blasting  and  the 
holes  for  the  charge  are  bored  by  machines.  A  battery  of  three 
or  four  drills  is  set  up  to  do  the  work  and  a  derrick  erected  for 
loading  the  stones  into  the  cars  or  wagons,  and  is  operated  by  a 
double-drum  reversible  engine.  The  steam  both  to  the  drills  and 
the  engine  is  supplied  by  a  boiler  of  about  60  H.P.  located  near 
by.  This  will  send  the  steam  to  the  work  through  an  iron  pipe 
line  with  T  joints,  where  connections  are  made  for  the  drills. 

When  the  work  is  so  large  that  more  than  one  battery  of  drills 


CHAINS,  ROPES,  BUCKETS,  ENGINES,  AND    MOTIVE    POWER.    271 

% 

is  employed,  the  several  batteries  will  be  widely  separated.  In 
such  a  case  the  steam  can  be  supplied  in  two  different  ways: 
either  by  numerous  boilers,  each  one  of  them  located  near  a  work- 
ing-point, or  else  by  a  single  boiler  of  large  capacity.  In  the 
former  case  it  will  be  necessary  to  employ  as  many  different 
boilers  along  the  work  as  there  are  points  of  attack.  This  will 
involve  heavy  expenses  on  account  of  the  extensive  plant,  the 
number  of  attendants  that  the  boilers  require,  the  great  number 
of  water-carriers  employed,  etc.  In  the  latter  case  it  will  necessi- 
tate a  boiler  plant  of  very  large  capacity  and  a  steam-pipe  line  of 
great  length.  It  is  well  known  that  steam  in  long  pipes  con- 
denses, and  consequently  there  will  be  a  large  amount  of  waste. 
It  will  then  be  more  economical  to  employ  some  more  convenient 
motive  power. 

For  the  reason  that  compressed  air  can  be  transmitted  even 
miles  without  any  sensible  loss  of  pressure  it  can  be  conveniently 
used  in  the  excavations  of  great  magnitude  and  greatly  extend- 
ing in  length.  The  plant  will  be  located  at  some  point  that 
will  be  convenient  for  handling  the  coal  and  water.  The  plant 
consists  of  a  certain  number  of  boilers  which  provide  steam 
to  drive  the  compressors.  The  air  compressed  is  stored  in  one 
or  more  receivers,  from  which  through  the  pipes  it  is  distributed 
to  the  various  working-points  along  the  line.  The  number  and 
capacity  of  the  boilers  as  well  as  that  of  the  compressors,  the 
dimension  of  the  receivers  and  the  diameter  of  the  various  pipes 
along  the  line  of  work,  should  be  in  proportion  to  the  expected 
work  and  must  be  fixed  by  the  engineer. 

Still  another  motive  power  to  be  used  in  works  of  excavation 
is  electricity.  Since  it  may  be  employed  for  different  purposes, 
as,  for  instance,  in  driving  the  drills  for  boring  the  holes  for  the 
charge  in  the  excavation  of  rocks,  in  driving  the  engines  for  hoist- 
ing materials,  and  for  hauling  the  trains  loaded  with  the  exca- 
vated earths,  it  has  certainly  great  advantages  over  any  other 
motive  power.  Besides  it  can  be  produced  and  transmitted  at 
a  smaller  expense  than  the  other  powers,  and  this  is  the  reason 
why  so  many  engineers  consider  electricity  as  "the  power"  for 


272  EARTH  AND  ROCK  EXCAVATION. 

any  work.  There  is  no  doubt  that  it  is  the  most  convenient 
motive  power  for  hauling  cars,  and  this  has  been  clearly  demon- 
strated on  the  enormous  development  of  electric  roads  built  and 
under  construction  all  through  the  world,  even  in  places  where 
steam  roads  would  have  been  a  great  failure.  But  although 
electricity  is  extensively  used  for  mining  purposes,  it  has  not  been 
adopted  yet  on  public  works,  and  this  is  perhaps  "due  more  to 
prejudice  than  to  any  real  good  reason. 

The  writer  knows  many  experiments  which  have  been  recently 
made  tending  to  demonstrate  that  electricity  is  the  most  eco- 
nomic motive  power  to  be  used  in  works.  Although  this  was  true 
in  the  particular  cases  considered  it  cannot  be  deduced  that 
such  a  statement  applies  to  every  case.  The  particular  condi- 
tions of  the  work  at  hand  as  well  as  those  depending  upon  the 
locality  in  which  the  excavation  is  made  should  be  taken  into 
consideration.  Electricity  is  transmitted  by  means  of  wires 
supported  by  simple  posts  which  can  be  erected  at  a  great  dis- 
tance from  one  another,  and  its  transmission  is  very  economical 
when  compared  with  the  cost  of  laying  down  an  iron  pipe  line 
for  compressed  air.  But  electricity  when  transmitted  to  a  dis- 
tance is  dispersed  on  account  of  the  resistances  encountered,  and 
only  a  part  of  that  produced  will  be  available  for  work.  In  using 
electricity  it  is  necessary  to  take  into  consideration  the  danger 
which  arises  from  the  presence  of  live  wires,  especially  when 
working  in  narrow  spaces,  as  in  the  trenches,  and  the  accidents 
that  may  befall  the  workmen.  For  these  reasons,  notwithstand- 
ing electricity  is  more  economic,  compressed  air  will  be  found  in 
the  end  the  most  convenient. 

In  regard  to  the  comparison  of  the  various  motive  powers  to 
be  used  in  the  work,  the  Engineering  News,  in  describing  Sec- 
tion 3  of  the  New  York  subway,  says: 

Before  compressed  air  was  adopted  as  a  motive  power  for 
the  subway  work  the  contractor  made  a  careful  study  as  to  the 
availability  of  steam  and  electricity.  Although  steam  appeared 
the  most  economical  it  necessitated  many  isolated  boilers  and 
engines,  with  endless  dirt  and  confusion,  besides  the  disadvantage 


CHAINS,  ROPES,  BUCKETS,  ENGINES,  AND    MOTIVE   POWER.    273 

of  working  many  union  engineers.  Electricity  appeared  eco- 
nomical, but  there  was  no  assurance  of  satisfaction  in  electric 
drills.  An  electric-power  plant  would  have  proved  an  expensive 
installation,  and  the  cost  of  electric  power  from  local  companies 
was  about  double  the  estimated  cost  of  compressed  air. 

The  adoption  of  compressed  air  on  this  section  was  quickly 
followed  by  'the  installation  of  similar  plants  for  other  sections 
of  the  subway,  and  it  has  proved  even  more  satisfactory  and 
economical  than  was  anticipated. 


CHAPTER  XIX. 

ANIMAL  AND  MECHANICAL  LABOR. 

ALL  excavation  is  done  by  men  working  in  gangs.  Each 
gang  is  in  charge  of  a  foreman,  and  they  are  all  under  the  direc- 
tion of  a  superintendent.  The  unit  of  work  is  the  day's  work, 
which  is  usually  ten  hours  for  all  but  mechanics,  who  work  an 
eight-hour  day.  When  the  work  is  carried  on  continuously,  one 
set  of  men  succeeding  another  at  intervals  of  six,  eight,  or  ten 
hours,  the  men  are  said  to  work  in  shifts.  The  number  of  men 
composing  a  gang  should  be  that  which  will  accomplish  the  most 
work  in  a  given  time  under  the  prevailing  conditions. 

Superintendent.  —  Honesty,  activity,  and  intelligence  com- 
bined with  a  large  amount  of  practical  experience  on  public  works 
are  the  requirements  of  a  good  superintendent.  He  must  super- 
vise the  work  and  direct  the  various  gangs,  so  that  it  is  accom- 
plished according  to  the  engineer's  plans,  which  he  must  be  able 
to  read  accurately.  He  must  know  how  to  stake  out  work;  how 
to  arrange  so  that  the  various  gangs  will  have  steady  work;  how 
to  detect  materials  that  are  not  according  to  specifications,  and 
how  to  measure  the  work  and  check  the  measurements  of  the 
engineer.  He  must  have  the  intelligence  and  practical  experi- 
ence which  will  enable  him  to  detect  error  or  imposition  on  the 
part  of  the  engineer,  and  to  oppose  orders  which  are  against  the 
interests  of  his  employer.  He  must  also  be  versatile  in  solving 
difficulties  which  occur  unexpectedly  in  the  work. 

Foremen. — Any  workman  so  well  acquainted  with  the  prob- 
lems and  intricacies  of  his  trade  that  he  is  not  only  able  to  do  the 
work  himself  but  to  direct  other  men  intelligently  can  be  em- 

274 


ANIMAL    AND    MECHANICAL    LABOR.  275 

ij 

ployed  as  a  foreman.  Forenjgn  should  not  be  appointed  through 
"pull,"  as  is  usuall^  the  case  in  nearly  all  public  work  in  this 
country,  but  they  should  be  selected  from  among  the  best,  most 
intelligent,  honest,  and  active  workmen.  The  duties  of  the  fore- 
man are  to  carry  out  the  orders  of  the  engineer  or  superintendent, 
and  to  dispose  of  the  workmen  in  such  a  manner  as  to  obtain 
from  them  the  most  efficient  work.  He  must  be  considerate 
with  his  men;  scolding  and  even  discharging  them  when  they 
are  lazy,  but  not  insulting  nor  continually  yelling  at  them,  or 
else  he  will  obtain  the  opposite  effect  to  the  one  he  desires.  The 
foreman  must  watch  out  for  defective  materials,  and  lay  them 
aside  for  the  engineer  or  superintendent  to  examine.  If  he  can 
keep  records  of  the  work  and  time  he  will  increase  his  value  by 
saving  the  services  of  a  timekeeper.  The  principal  duty  of  the 
foreman  is  to  look  after  the  interests  of  his  employer,  and  to  this 
end  he  must  closely  watch  his  men  to  see  that  none  is  ever  without 
work,  and  that  time  is  not  lost  in  shifting  from  one  task  to  another. 
He  must  warn  the  men  of  danger,  and  watch  out  against  the  dan- 
ger of  accident.  In  rock  excavation  he  must  be  perfectly  ac- 
quainted with  drilling-machines,  and  have  a  thorough  knowledge 
of  blasting.  He  must  locate  the  position  of  the  holes  to  be 
drilled,  and  fix  their  depth  after  these  have  been  determined 
in  a  general  way  by  the  engineer.  He  must  take  personal  charge 
of  dynamite  and  other  explosives;  he  must  make  the  prepara- 
tions for  blasts,  and,  generally,  he  will  take  charge  of  the  firing 
operations,  establishing  the  danger-lines  and  seeing  that  all  per- 
sons and  machinery  are  out  of  danger  from  injury  by  the  blast. 

Classification  and  Capacity  of  Workmen. — Excavation  is  per- 
formed either  by  manual  labor  or  by  machines,  consequently 
the  men  employed  in  any  work  can  be  grouped  into  mechanics 
and  laborers.  Mechanics  are,  as  a  rule,  intelligent  and  educated 
men,  having  a  good  knowledge  of  the  principles  of  mechanics  and 
wide  experience  and  skill  in  their  trade.  As  engine-drivers  have 
to  possess  a  State  certificate  which  is  obtained  only  after  passing 
an  examination,  they  may  be  assumed  to  be  always  well  acquainted 
with  their  trade.  Membership  in  the  labor  unions  is  also  a  guar- 


276  EARTH  AND  ROCK  EXCAVATION. 

antee  that  a  mechanic  is  competent  to  do  the  work  for  which  he 
is  employed. 

Of  late  years,  because  of  the  extensive  and  increasing  use  of 
drilling-machines  in  rock  excavation,  and  the  simplicity  of  these 
machines,  which  do  not  necessitate  special  mechanical  skill  in  their 
handling,  contractors  have  taken  to  operating  them  by  intelligent 
laborers.  These  get  better  wages  than  ordinary  laborers,  but 
smaller  wages  than  mechanics,  and  form  a  middle  class  between 
the  two.  The  duty  of  the  drillers  is  to  regulate  the  lowering  of 
the  machine,  change  the  bits,  and  remove  the  drills  from  one 
place  to  another  according  to  the  orders  of  the  foremen.  Drillers 
must  take  great  care  of  the  machine  entrusted  to  them,  and  must 
be  active,  steady,  and  patient  in  their  work,  since  the  success  of 
the  drilling  depends  upon  them.  They  must  thoroughly  under- 
stand the  drilling-machine  and  its  work,  and  be  able  to  change 
the  defective  parts  for  the  new  ones. 

All  works  of  excavation,  whether  of  rock  or  earth,  when  not 
done  by  machine  are  done  exclusively  by  ordinary  laborers.  In 
this  country  contractors  and  engineers  do  not  pay  great  atten- 
tion to  the  work  of  their  laborers,  who  receive  the  same  wages, 
varying  from  $1  to  $1.50  per  day.  The  writer  thinks  this  a  great 
mistake,  since  there  are  many  laborers  not  worth  half  of  what 
they  get,  while  there  are  others  that  deserve  more  than  twice 
what  they  usually  get.  Standard  wages  are  possible  with  me- 
chanics, especially  when  from  a  union,  because  the  simple  fact  of 
membership  in  the  union  is  a  proof  of  their  ability,  and  so  when 
a  contractor  engages  one  of  these  men,  he  knows  what  his  ability 
is,  and  consequently  what  he  may  expect  from  him.  But  when 
a  contractor  engages  a  shoveler  for  instance,  at  the  prevailing 
wages,  he  does  not  know  what  kind  of  workman  he  is,  and  what 
he  is  able  to  do.  The  shoveler  may  be  a  strong  man  and  one 
with  experience,  or  he  may  turn  out  to  be  a  man  who  never  did 
any  similar  work  before,  but  took  the  shovel  as  the  last  resort 
against  starvation. 

As  a  rule  the  cheapest  work  is  obtained  from  men  getting  the 
highest  wages.  The  author  knows  of  an  experiment  made  by 


ANIMAL    AND    MECHANICAL    LABOR.  277 

the  Italian  Engineering  Cor™  in  Rome,  in  which  the  work  of 
the  different  laborers"  was  accurately  tested.  The  laborers  were 
divided  into  three  gangs,  according  to  the  locality  they  came 
from  and  the  wages  they  were  used  to  getting,  these  being  40 
cents,  50  cents,  and  $1,  respectively.  The  work  was  ordered  to 
go  on  as  usual  without  the  laborers  knowing  that  the  efficiency 
of  their  work  was  to  be  tested.  After  a  couple  of  weeks  the  work 
of  the  different  gangs  was  measured,  and  it  was  found  that  the 
workmen  paid  at  $1  per  day  did  more  than  twice  the  work  done 
by  those  paid  at  50  cents  and  nearly  three  times  that  done  by 
the  laborers  at  40  cents.  It  was  also  ascertained  in  this  case  that 
highest-priced  labor  was  the  cheapest  in  the  end. 

The  diet  of  the  laborers  has  a  great  influence  upon  the  effi- 
ciency of  their  work;  a  properly  fed  man  gives,  as  a  rule,  a  greater 
amount  of  work  than  a  poorly  fed  one.  This  fact  is  of  special 
importance  to  contractors  where  on  account  of  the  location  of 
the  work  they  must  either  directly  or  by  contract  furnish  pro- 
visions to  their  men.  It  is  to  their  interest  to  see  that  the  men 
are  properly  fed.  Sometimes  the  contractors  sell  their  men  poor 
foods,  or  when  good  it  is  sold  at  very  high  prices.  In  both  cases 
the  losers  are  the  contractors.  In  the  example  referred  to  above, 
in  investigating  the  diet  of  the  various  gangs  of  laborers  it  was 
found  that  the  men  who  did  the  greater  amount  of  work  were 
well  fed,  having  two  meals  a  day,  their  diet  consisting  of  fresh 
meat  and  bread  and  wine.  Those  paid  at  50  cents  got  two  meals 
a  day,  one  consisting  simply  of  bread  and  cheese  and  the  second 
of  corn-meal  and  vegetables  and  salt  meat  or  fish,  with  a  little  wine 
or  none  at  all.  The  diet  of  the  laborers  at  40  cents  per  day  was 
even  poorer. 

Laborers  must  be  steady  in  their  work;  a  slow  but  continuous 
speed  of  work  is  far  more  efficient  than  one  began  at  a  high  rate 
and  slowing  down  continuously  all  through  the  day.  A  man 
cannot  work  continuously,  but  needs  rest,  and  the  best  way  is  to 
alternate  the  periods  of  his  work  with  the  moments  of  rest.  The 
more  regularly  these  are  alternated  the  greater  will  be  the  endur- 
ance of  the  man  and  consequently  the  more  efficient  will  be  his 


278  EARTH  AND  ROCK  EXCAVATION. 

work.  An  intelligent  contractor  should  prevent  the  yelling  and 
" hurry-up"  orders  given  continuously  by  ignorant  foremen.  By 
this  procedure  they  intend  to  show  their  attachment  to  the  work 
and  in  their  ignorance  honestly  believe  that  they  are  looking 
after  the  interest  of  the  contractor,  while  they  are  obtaining  just 
the  opposite  result.  These  foremen  should  be  immediately  dis- 
charged. There  are  still  contractors,  however,  though  happily 
very  few,  who  believe  that  the  only  way  of  obtaining  efficient 
work  from  the  men  is  by  yelling  and  scolding.  Mr.  George  H. 
Parker,  a  civil  engineer  in  charge  of  the  works  at  Keney  Park, 
Hartford,  Conn.,  states  that  while  the  work  of  handling  10  or 
12  cu.  yds.  of  earth  is  considered  a  fair  day's  work,  he  has  obtained 
a  work  of  loading  20  or  more  cu.  yds.  per  day  with  the  same  effort. 
He  found  that  the  actual  time  for  handling  the  sand  per  shovel 
was  from  fifteen  to  twenty-five  seconds,  and  then  he  ordered  each 
man  to  work  twenty-five  seconds  and  rest  twenty-five  seconds 
alternately  through  the  day.  To  this  quick  work  and  then  an 
absolute  and  unquestioned  right  to  rest  for  an  equal  time  he 
ascribes  the  success  of  his  system.  Mr.  Parker  also  found  that 
his  men  worked  the  quickest  in  the  morning,  slower  in  the  after- 
noon, and  still  slower  at  night.  In  like  manner  Monday  was 
the  laborer's  best  day  and  Saturday  his  worst  day  as  a  rule, 
though  weather  conditions  modify  this. 

Apart  from  any  humanitarian  or  philanthropic  idea,  laborers 
are  considered  by  engineers  and  contractors  simply  as  living 
working-machines;  they  are  hired  and  paid  for  their  work,  and 
consequently  it  is  necessary  to  know  the  amount  of  work  to  be 
expected  from  them. 

In  the  English-speaking  world  work  is  measured  by  the  foot- 
pound, which  is  the  effort  required  to  raise  1  Ib.  in  weight  to  1  ft. 
in  height.  In  Europe  and  everywhere  else  where  the  metric 
system  has  been  adopted,  the  unit  of  measure  of  work  is  the 
kilogrammeter,  or  the  effort  required  to  raise  the  weight  of  1  kilo- 
gram to  the  height  of  1  meter.  A  kilogrammeter  is  equal  to  7.21 
ft.-lbs.  A  man  can  exert  in  a  day  only  a  certain  amount  of  effort 
and  no  more ;  thus  his  daily  work  can  be  valued  by  the  foot-pounds 


ANIMAL    AND    MECHANICAL    LABOR. 


279 


he  can  lift  in  a  day.  This  njmiber  has  been  variously  estimated 
by  different  authors.  *  Rankine  says  that  the  daily  effort  exerted 
by  the  muscular  strength  of  a  man  is  the  product  of  three  quan- 
tities— the  useful  resistance,  the  velocity  with  which  that  resist- 
ance is  overcome,  and  the  number  of  units  of  time  per  day  during 
which  work  is  continued.  For  each  individual  man  there  is  a 
certain  set  of  values  of  these  three  quantities  which  makes  their 
product  a  maximum,  and  it  is  therefore  the  best  for  economy  of 
power;  and  any  departure  from  that  set  of  values  diminishes  the 
daily  effect. 

The  following  table  of  the  effects  of  the  strength  of  men  em- 
ployed in  various  ways  was  compiled  by  Rankine  from  the  works 
of  Poncelet,  General  Morin,  and  others. 


R, 

Lbs. 

V, 

Feet 
per 
Second. 

T, 
3600 
Hours 
per 
Day. 

RV, 
Ft.-lbs. 

RVT, 

Ft.-lbs. 
per  Day. 

1 

Raising  his  own  weight  up  stairs 
or  ladders 

143 

0.5 

8 

72.5 

2,038,000 

2 

Raising  his  own  weight  up  stairs 
or  ladders                          .    .    . 

143 

0.5 

10 

72.5 

2,616,000 

3 
4 
5 
6 

Hauling  up  weight  with  rope  .... 
Lifting  weights  by  hand  
Carrying  weights  up  stairs  
Shoveling  up  earth  to  a  height  of 
5  ft    3  ins 

40 
44 
143 

6 

0.75 
0.55 
0.13 

1  3 

6 
6 
6 

10 

30 
24.2 
18.5 

7.8 

648,000 
522,720 
399,600 

280,800 

7, 

8 
9 

Wheeling  earth  in  barrows  up  slope 
1  in  12  with  horizontal  velocity 
9  ft.  per  sec.  (returning  empty)  . 
Pushing  or  pulling  horizontally.  .  . 
Turning  a  crank  or  winch 

132 

26.5 
18 

0.075 
2.00 
2  5 

10 

8 
8 

9.9 
53 
45 

356,400 
1,526,400 
1,296,000 

10 

Working  pump  

13.2 

2.5 

10 

33 

1,188,000 

11 

Hammering 

15 

? 

8? 

? 

480,000 

Colombo  in  his  ''Engineers'  Handbook"  gives  the  following  data: 
"  The  average  work  per  second,  working  all  day  long,  can  be  assumed 
between  6  and  9  kilogramme ters,  being  equal  to  one-twelfth  or 
one-eighth  of  a  horse-power.  Working  alternately  with  periods  of 
rest  his  effort  can  be  considered  as  varying  between  18  and  24 
kilogrammeters.  Working  continuously  on  a  crank  with  a  velocity 
of  .75  or  .9  meter  per  second  his  effort  can  be  assumed  as  between 
8  and  10  kilogrammeters,  while  working  for  a  short  time  only 


280  EARTH  AND  ROCK  EXCAVATION. 

followed  by  long  stretches  of  rest  he  may  exert  efforts  equal  to 
25  or  30  kilogrammeters  per  second. 

' '  The  maximum  efforts  that  a  man  can  exert  in  pulling  or  push- 
ing for  a  short  time  only  is  between  50  and  60  kilogrammeters.  He 
can  lift  a  weight  of  200  or  300  kgms.,  and  carry  on  his  shoulders  a 
weight  of  150  or  200  kgms.  A  man  can  walk  with  a  velocity  of 
1.25-1.40  meters  per  second;  in  walking  fast  he  can  cover  a  dis- 
tance varying  from  1.50  to  1.70  meters  per  second,  and  he  can  run 
from  2.20  to  7  meters  per  second/' 

The  muscular  strength  of  animals  is  utilized  in  different  ways 
in  public  works;  the  principal  ones  being  in  carrying  materials  on 
their  backs,  as  in  mountain  regions,  or  in  pulling  them  in  carts 
and  wagons.  The  animals  generally  used  are  mules  and  horses. 
Mules  are  tougher  and  will  endure  more  hard  work  than  horses; 
the  former  are  very  useful  in  mountain  work,  but  horses  are 
more  commonly  employed  for  hauling  carts  and  wagons. 

Mules,  when  transporting  materials  on  their  back,  can  easily 
carry  weights  varying  from  200  to  400  Ibs.,  and  travel  long  dis- 
tances; for  short  trips  they  will  usually  carry  from  360  to  500 
Ibs.  on  horizontal  roads.  They  move  with  a  velocity  which  can 
be  assumed  at  3  miles  per  hour  on  ordinary  roads,  but  going  up 
incline  they  do  not  travel  more  than  2J  miles  per  hour.  The 
total  distance  traveled  in  a  day  can  be  considered  at  20  miles. 

Horses  hitched  to  the  carts  and  wagons,  according  to  the  con- 
dition of  the  road,  may  carry  loads  varying  from  1200  to  2500  Ibs. 
besides  the  weight  of  the  vehicle.  The  average  weight  of  a  cart 
can  be  assumed  at  1300  Ibs.,  and  since  in  doubling  the  number 
of  horses  there  it  is  not  necessary  to  increase  the  weight  of  the 
cart,  the  greater  will  be  the  quantity  of  the  hauled  materials,  and 
this  is  the  reason  why,  in  order  to  better  utilize  the  strength  of 
animals,  they  are  worked  in  teams,  and  why  cars  are  constructed 
for  two,  three,  and  four  horses.  Two  horses  can  easily  haul  3000 
Ibs.,  three  horses  4500  Ibs.,  and  four  horses  6200  Ibs.  Besides 
it  is  more  convenient  to  have  the  horses  work  in  teams  than  alone, 
on  account  of  the  wages  of  the  driver.  On  carts  hauled  by  only 
one  horse,  which  has  also  to  drag  the  total  weight  of  the  cart,  the 


ANIMAL    AND    MECHANICAL    LABOR. 


281 


wages  of  the  driver  must  be  jaid  entirely  by  the  small  quantity 
of  material  hauled;  while,  if  working  in  teams,  the  total  work  of 
the  second  horse  will  be  utilized  exclusively  for  hauling  material, 
and  only  half  the  wage  of  the  driver  must  be  paid  by  the  work  of 
each  horse. 

The  following  table,  given  by  Gasparin,  clearly  indicates  the 
efficiency  of  the  work  of  horses  working  alone  and  in  teams : 


Useful  Load. 

Load  per 
Horse. 

Weight  of 
Vehicle. 

Total. 

Average 
Load  per 
Horse. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Lbs. 

Cart,  1  horse  

2070 

2070 

1100 

3,170 

3170 

Wagon,  2  horses  .  .  . 

4349 

2173 

1980 

6,329 

3164 

3 

6012 

2004 

2640 

8,652 

2884 

4 

8140 

2035 

2970 

11,110 

2777 

5 

8635 

1727 

3300 

11,935 

2387 

6 

8672 

1445 

3300 

11,972 

1978 

7 

8751 

1249 

3300 

12,051 

1721 

8 

7444 

1012 

3300 

10,744 

1343 

From  this  it  is  seen  that  it  is  economy  to  increase  the  number  of 
the  horses  up  to  a  certain  limit,  which  is  four.  Beyond  this  num- 
ber the  efficiency  of  the  work  of  each  horse  greatly  decreases. 

In  this  book,  for  calculating  the  cost  of  hauling  materials 
when  animals  were  employed  as  motive  power,  the  price  of  hiring 
teams  was  usually  taken  into  consideration.  But  if  a  more  accu- 
rate analysis  should  be  required,  the  cost  could  be  easily  found 
by  considering  the  following  items:  Interest  on  the  capital  invested 
in  acquiring  the  horses,  daily  cost  of  maintenance,  including  the 
food,  stable,  stableman,  insurance,  'medicine,  shoes,  etc.,  and  sink- 
ing fund.  The  total  amount  divided  by  the  number  of  working 
days  in  a  year  will  give  the  correct  cost  of  the  daily  work  of  a 
horse. 

The  work  of  horses  has  been  variously  estimated  by  different 
authors.  Rankine  deduces  the  efficiency  of  their  work  by  taking 
into  consideration  the  same  three  elements  he  employs  for  calcu- 
lating the  muscular  strength  of  men,  viz.,  the  resistance,  the 
velocity,  and  the  time,  and  he  considers  the  work  on  the  product 
of  these  three  quantities: 


282 


EARTH    AND    ROCK    EXCAVATION. 


R. 

V, 
Feet 

Q  per. 
Second. 

T. 

RV. 

RVT. 

Cantering  and  trotting,  draw-   I 
ing  light  railway  carriage.  .  .  1 

Horse  drawing  cart. 

Min.     22£  ) 
Mean   30^  [• 
Max.    60j  ) 
120 

3.6 

4 

8 

432 

6,444,000 
12  441  600 

Colombo  in  his  handbook  for  engineers  gives  the  following 
data:  "A  horse  working  all  day  can  drag  a  weight  varying  between 
40  and  60  kgms.  per  second,  corresponding  to  40  or  50  kilo- 
grammeters,  equivalent  to  ^  or  f  of  a  horse-power.  For  a  short 
time  he  can  drag  a  weight  of  250  to  400  kgms.  per  second.  The 
speed  of  the  horse  in  running  is  14  meters  per  second,  galloping 
10  meters,  trotting  from  4.4  to  3.3,  walking  fast  about  2  meters, 
and  in  ordinary  walking  from  0.90  to  1  meter.  On  good  horizontal 
roads  a  horse  may  drag  besides  the  vehicle  a  load  of  350  to  500 
kgms.  when  trotting,  and  between  1000  and  1500  kgms.  when 
walking.7' 

A  whole  book  could  be  written  concerning  the  manner  of 
working  the  various  machines  already  described.  The  general 
characteristics  of  several  of  the  principal  mechanical  appliances 
used  in  the  excavation  of  earth  and  rock,  as  well  as  for  transporta- 
tion purposes,  have  been  given  in  the  preceding  chapters;  a  little 
space  will  be  devoted  here  to  the  machines  as  considered  from  a 
general  point  of  view. 

In  the  selection  of  any  machine  it  is  the  duty  of  the  engineer 
to  carefully  examine  the  various  conditions  of  the  work,  and  to 
decide  which  of  the  various  machines  will  be  the  most  efficient 
in  the  particular  case  he  has  to  deal  with.  To  facilitate  such  a 
selection,  in  the  description  of  the  various  kinds  of  machines  re- 
viewed in  the  preceding  chapters,  it  has  been  indicated  in  what 
circumstance  the  work  of  each  machine  will  be  the  most  efficient. 
Once  the  engineer  has  selected  the  type  of  machine  most  conve- 
nient for  his  case,  he  should  get  the  catalogues  of  the  various 
manufactures,  thus  providing  himself  with  a  full  description  of 
the  different  machines  of  the  same  type  that  are  found  on  the 


ANIMAL    AND    MECHANICAL    LABOR.  283 

market.  Since  all  these  machines,  as  a  rule,  are  very  similar  in 
their  principal  parts,  aJthouglAhey  greatly  differ  in  the  details, 
and  since  every  manufacturer  will  represent  his  machine  as  the 
best  and  most  efficient  of  all,  it  will  be  desirable  for  the  engineer 
to  obtain  from  the  manufacturers  a  list  of  places  where  their 
machines  are  at  work.  By  visiting  these  places  the  engineer 
can  personally  ascertain  from  the  men  in  charge  of  the  machines 
their  advantages  and  defects.  Keeping  record  of  the  efficiency 
of  the  work  of  every  machine,  and  the  statement  of  the  various 
engineers  in  charge  of  the  machines,  it  will  be  very  easy  to  select 
the  best  machine  by  a  simple  comparison. 

As  a  rule  the  most  desirable  machines  are  those  solidly  built 
and  provided  with  the  smallest  possible  number  of  parts  all  inter- 
changeable, and  those  which  will  perform  the  work  at  the  lowest 
figure.  The  price  should  not  have  influence  on  the  selection  of  a 
machine,  because  in  many  instances  a  very  expensive  machine 
is  not  always  the  best,  and  a  very  cheap  machine  is  usually  found 
in  the  end  to  be  the  most  expensive. 

Together  with  the  description  of  the  various  machines,  there 
has  been  given  also  the  cost  of  the  unit  of  volume  of  the  work 
performed.  This,  however,  cannot  be  taken  as  the  real  cost, 
because  it  was  based  exclusively  on  the  working  expenses  of  the 
machine.  There  are  other  general  items  to  be  considered  which 
tend  greatly  to  alter  the  cost  of  the  unit  of  volume  of  the  work. 
These  are-  the  interest  on  the  capital  invested  in  the  machine,  the 
probability  of  continuous  work,  the  necessary  repairing  required 
to  keep  the  machine  in  good  working  order,  and,  finally,  the 
sinking-fund. 

The  interest  of  the  capital  invested  in  the  contractor's  plant 
is  a  negligible  quantity  when  the  plant  consists  only  of  hand- 
tools,  but  it  assumes  great  importance  when  it  contains  several 
large  machines.  If  the  capital  invested  in  purchasing  machines 
had  been  invested  in  any  other  commercial  investment,  it  would 
have  certainly  given  in  return  an  interest  of  5  or  6  per  cent, 
per  annum.  By  purchasing  the  machine  the  contractor  does 
not  get  any  more  this  return  from  his  money,  and  he  must  obtain 


284  EARTH  AND  ROCK  EXCAVATION. 

it  from  the  work  of  the  machine.  Consequently,  before  calculat- 
ing the  net  profits  of  any  operation,  amongst  the  yearly  expenses 
of  any  machine  should  be  considered  first  the  interest  of  the 
invested  capital  at  the  commercial  ratio. 

In  buying  a  machine  it  is  necessary  to  consider  also  the  prob- 
ability that  the  contractor  has  of  getting  continuous  work.  In 
fact,  if  a  machine  is  bought  for  a  single  work,  notwithstanding  its 
running  expenses  are  so  low  as  to  perform  the  work  at  a  small 
cost,  this  is  not  really  the  case  because  of  the  other  expenses  to  be 
charged  to  this  work  alone,  and  which  tend  to  greatly  increase 
the  cost  of  the  unit  of  volume  of  the  work.  There  is  no  doubt 
that  machines  tend  to  lessen  the  cost  of  work,  but  to  do  so  they 
must  work  as  continuously  as  possible.  Suppose  that  the  yearly 
expenses  of  a  machine,  including  interest,  sinking-fund,  etc.,  will 
amount  to  $700;  if  the  machine  is  working  200  days  per  year  it 
will  be  necessary  to  add  $2.50  to  its  daily  expenses;  while  if  it 
works  only  50  days  in  a  year  the  daily  expenses  must  be  increased 
by  $14.  Considering  the  capacity  of  the  machine  at  500  cu.  yds. 
per  day  in  the  former  case  the  cost  of  the  work  would  be  increased 
by  only  ^  cent  per  cu.  yd. ;  while  in  the  second  case  the  cost  would 
be  increased  by  nearly  3  cents  per  cu.  yd. 

Another  important  item  to  be  considered  in  machines  is  the 
wearing  and  repairing.  Machines,  no  matter  how  strong  they 
are  built,  will  undergo  wear,  especially  on  the  parts  which  are 
most  subjected  to  sudden  strains.  To  keep  these  machines  in 
good  working  order  it  is  necessary  to  repair  them  continuously. 
It  will  then  be  necessary  to  spend  every  year  a  certain  amount  of 
money  in  order  to  keep  the  machine  in  good  condition.  Such 
an  amount  varies  with  the  machine,  the  quality  of  the  soil  handled, 
and  other  circumstances.  The  sum  which  is  usually  laid  aside 
every  year  for  repairing  varies  between  one-third  and  one-fifth 
of  the  total  cost  of  the  machine,  and  such  a  sum  should  be  sub- 
tracted from  the  profits  of  the  operation  to  obtain  the  net  profit. 

Another  important  item  in  connection  with  the  calculation  of 
the  cost  of  the  unit  of  volume  of  the  work  performed  by  the 
machine  is  the  sinking-fund.  Any  machine,  notwithstanding 


ANIMAL    AND    MECHANICAL    LABOR.  285 

it  is  kept  in  good  order,  wilf  last  only  for  a  certain  number  of 
years,  and  then  the  repairing  that  will  be  required  to  keep  the 
machine  in  working  order  will  be  so  great  that  it  will  be  more 
economical  to  buy  a  new  machine  than  to  renew  all  the  various 
parts  of  the  old  one.  The  money  for  the  acquisition  of  a  new 
machine  should  be  obtained  from  the  work  of  the  former  machine. 
In  fact,  if  a  contractor  pockets  every  year  the  profits  got  from  the 
work,  without  laying  aside  an  amount  of  money  which,  with  its 
accumulated  interests,  after  so  many  years  will  give  the  original 
amount  of  the  cost  of  the  machine  with  which  to  buy  a  new  one 
when  the  old  is  gone,  he  will  also,  together  with  the  so-called 
dividends,  pocket  part  of  the  capital.  The  sinking-fund  is  that 
sum  which  it  is  necessary  to  lay  aside  every  year,  so  that  after  a 
given  number  of  years  these  sums,  together  with  their  accumulated 
interest,  will  give  the  required  amount  required  to  buy  a  new 
machine. 

The  writer  has  often  noticed  that  the  sinking-fund  is  an  item 
easily  forgotten  in  this  country.  A  few  years  ago  one  of  the  great 
railroad  systems  of  the  country,  whose  shares  were  quoted  above 
par  on  account  of  the  big  dividend  paid  for  some  years  in  succes- 
sion, all  at  once  went  into  the  hands  of  the  receiver,  and  the  value 
of  the  shares  fell  near  to  nothing.  The  reason  of  such  a  sudden 
change  was  that  the  old  administration  never  thought  of  the 
sinking-fund,  which  was,  instead,  distributed  to  the  shareholders 
as  dividends.  The  consequence  was  that  the  rolling-stock  was 
old  and  needed  to  be  renewed,  and  as  no  money  for  such  a  purpose 
had  been  laid  aside  in  the  previous  years,  in  order  to  provide  it, 
it  was  found  necessary  to  reorganize  the  company  and  borrow 
money.  Now,  if  even  the  big  railroad  corporations  sometimes 
overlook  such  an  important  item,  it  may  easily  be  forgotten  by 
contractors. 

Expensive  machines,  notwithstanding  they  are  continuously 
repaired,  will  not  last  longer  than  twenty  years,  and  consequently 
it  is  necessary  to  lay  aside  every  year  a  certain  sum  which,  together 
with  its  compound  interest  at  the  end  of  twenty  years,  will  give 
the  original  cost  of  the  machine,  so  as  to  have  at  hand  the  sum  to 


286 


EARTH    AND    ROCK    EXCAVATION. 


buy  a  new  machine,  thus  perpetuating  the  capital;  otherwise,  part 
of  its  capital  will  have  been  destroyed.  The  age  of  a  machine 
varies  between  ten  and  twenty  years;  tools  last  only  a  few  months. 
The  sum  which  it  is  necessary  to  lay  aside  every  year  is  cal- 
culated by  means  of  the  formula 


in  which  r  is  the  annual  interest  of  a  dollar,  S  the  total  amount  of 
the  sum  required  after  so  many  years,  and  n  the  number  of  years. 

^e  Different  years  and  rate 


The  various  values  of 


(1+T)»-1 

of  interest  are  given  in  the  following  table: 


Number  of 
Years. 

n  =  4  Per 
Cent. 

n  =  5  Per 
Cent. 

n  =  6  Per 

Cent. 

1 

1.000 

1.000 

1.000 

2 

0.4902 

0.4878 

0.4854 

3 

0.3203 

0.3172 

0.3141 

4 

0.2355 

0.2320 

0.2286 

5 

0.1846 

0.1810 

0.1774 

6 

0.150S 

0.1470 

0.1434 

7 

0.1266 

0.1228 

0.1191 

8 

0.10S5 

0.1047 

0.1010 

9 

0.0945 

0.0909 

0.0870 

10 

O.OS33 

0.795 

0.0759 

12 

0.0665 

0.0623 

0.0593 

15 

0.0499 

0.0463 

0.0430 

20 

0.0336 

0.0302 

0.0272 

25 

0.0240 

0  .  0209 

0.0182 

CHAPTER  XX. 


THE  DIRECTION  OF  EXCAVATION  WORK. 


IT  is  not  an  easy  matter  to  correctly  direct  a  work  of  excava- 
tion, and  as  a  rule  the  most  successful  contractor  is  he  who  handles 
the  materials  in  the  most  economical  way.  No  general  rules  can 
be  given  for  organizing  a  work  of  excavation,  every  one  present- 
ing some  characteristic  differences  which  only  the  keenest  obser- 
vation can  detect,  and  from  them  suggest  means  to  overcome 
the  difficulties  in  the  simplest  and  easiest  manner.  To  give, 
however,  an  idea  of  how  the  work  should  be  directed,  several 
cases  will  be  considered  here,  which  vary  with  the  extent  and 
magnitude  of  the  work,  and  also  with  the  manner  of  excavating 
and  the  means  of  transportation  adopted.  For  the  sake  of  classi- 
fication a  few  .cases  will  be  reviewed  here  in  the  following  order  : 


Cut  of  small  depth 
extending  over  a 
large  area. 


Cut  done  by  plows. 


Transportation 
scrapers. 


by 


Cut    done    by    New   Era  j  Transportation     by 
grader.  (       carts  and  wagons. 


Cut  done  by  hand. 


Cut    deep    and 
and  narrow. 


long 


Transportation  by 
wheelbarrows. 

Transportation  by 
carts  and  wagons. 

Transportation  by 
industrial  rail- 
ways. 


t  Up-digger. 

The   excavation   of    earth   extending   over   a   large   area   of 
small  depth  can  be  conveniently  performed  by  means  of  a  plow 

237 


288  EARTH  AND  ROCK  EXCAVATION. 

and  the  materials  removed  by  scrapers,  which  can  be  either  of 
the  drag  or  wheel  types.  The  average  work  of  a  plow  in  heavy 
soil  can  be  assumed  at  250  cu.  yds.,  while  in  light  soil  it  can 
remove  on  an  average  500  cu.  yds.  In  directing  the  work  exe- 
cuted by  means  of  scrapers  it  is  of  great  importance  to  know  (1) 
the  number  of  scrapers  to  be  employed  per  each  plow;  and  (2) 
the  manner  in  which  the  work  should  be  arranged. 

In  regard  to  the  number  of  scrapers  to  be  employed,  this 
varies  with  the  quality  and  capacity  of  the  scrapers  and  the  dis- 
tance to  which  the  materials  must  be  hauled.  Drag-scrapers  are 
very  convenient  for  short  hauls.  It  has  been  seen  that  they  may 
haul  from  74  to  11  cu.  yds.  per  day,  according  to  the  distance, 
varying  from  100  to  600  ft.  In  heavy  soil  a  single  plow  will  give 
work  to  3.5  drag-scrapers  hauling  the  materials  to  100  ft.  distance; 
it  will  require  7  drag-scrapers  to  haul  the  same  quantity  of  mate- 
rial to  200  ft.,  and  2  drag-scrapers  should  be  added  for  each  100  ft. 
in  length  over  200  ft.  distance.  When  the  material  is  very  loose, 
so  that  the  average  quantity  of  earth  removed  by  the  plow  in  a 
day  is  about  500  cu.  yds.,  each  plow  will  give  work  to  a  number 
of  drag-scrapers  double  that  indicated  above  for  the  heavy  soils, 
and  consequently  for  distances  greater  than  200  ft.  one  scraper 
should  be  added  for  each  25  ft.  in  length  of  the  haul. 

Wheeled  scrapers  are  far  more  economical  for  long  hauls  than 
drag-scrapers.  They  are  of  different  capacity,  varying  from  9  to 
14  cu.  ft.,  and  since  the  work  of  the  plow  will  remain  the  same, 
the  number  of  the  wheeled  scrapers  required  to  remove  the  earth 
loosened  by  the  plow  will  be  smaller.  This  number,  however, 
will  vary  with  the  capacity  of  the  scraper.  Thus  3.5  wheeled 
scrapers  of  9  ft.  capacity  will  be  required  to  haul  to  200  ft.  dis- 
tance the  earth  removed  by  a  plow  in  a  day's  work;  5.5  to  300  ft.; 
7.5  for  400  ft.  distance,  and,  in  general,  2  scrapers  more  for  every 
100  ft.  in  additional  length.  A  larger  number  of  wheeled  scrapers 
will  be  required  for  removing  the  earth  where  it  is  sandy  and 
light,  and  as  a  rule  in  such  a  case  a  number  of  scrapers  double 
the  one  required  for  heavy  soil  will  be  required.  When  wheeled 
scrapers  of  large  capacity  are  employed  the  number  of  scrapers 


THE    DIRECTION    OF    EXCAVATION   WORK. 


289 


will  be  2.5  for  200  ft.  distanc*,  3.5  for  300  ft.,  5  for  400  ft.,  and  1 
more  scraper  for  every  100  ft.  increased  distance  of  haul,  and 
double  this  number  for  sandy  and  light  soils. 

In  regard  to  the  manner  of  arranging  the  work,  it  is  necessary 
to  observe  that  the  scrapers  should  travel  continuously,  and 
consequently  they  must  travel  in  circles  or  at  least  along  two 
parallel  roads  with  a  loop  at  each  end.  Scrapers  in  earthwork 
excavations  can  be  employed  in  building  up  embankments  from 
cuts  or  borrow-pits,  in  leveling  the  ground  for  reservoirs  or  large 
railroad  yards  or  sites  for  factories,  or  in  the  transportation  of 
earth  from  the  point  of  excavation  to  the  point  of  loading  into 
more  powerful  and  economical  vehicles. 

Fig.  136  clearly  indicates  the  manner  of  building  embank- 
ments for  new  roads,  when  the  earth  is  taken  from  along  the  sides 


FIG.  136. 

of  the  road.  The  embankment  is  built  up  in  layers  18  ins.  deep 
each,  and  they  succeed  each  other  in  such  a  way  as  not  to  inter- 
fere with  one  another.  The  work  proceeds  on  both  sides  of  the 
axis  of  construction  at  the  same  time,  and  follows  the  order  indi- 
cated in  the  figure.  At  first  a  battery  composed  of  several  scrapers 
works  in  section  1,  building  up  half  of  the  embankment,  with  the 
slope  reaching  the  lateral  terminal  of  the  projected  road;  10  ft.  or 


X^^^^N 

f**     OF  THE  A 

(  UNIVERSITY   I 


290  EARTH  AND  ROCK  EXCAVATION. 

more  away  another  gang  works  on  the  other  side  of  the  axis  of 
the  construction,  as  indicated  at  2  in  the  figure.  A  third  gang 
then  follows  at  3,  at  a  distance  not  less  than  10  ft.  away  from  2 
and  20  ft.  from  1,  and  builds  another  layer  above  the  one  that 
has  been  previously  placed.  The  following  gang,  4,  builds  the 
other  portion  of  the  embankment  on  the  other  side  of  the  axis 
of  construction.  In  this  manner  the  embankment  is  built  for  a 
height  of  36  ins.;  but  if  it  is  required  to  be  still  higher,  other 
gangs  can  be  employed  in  succession  to  those  mentioned. 

The  earth  is  taken  from  along  the  lines  ra,  n,  and  op  at  the 
left  and  right  of  the  embankment  to  be  constructed,  and  the 
trenches  can  be  used  as  drains  for  the  road.  The  earth  can  be 
removed  by  one  plow  or  more,  according  to  the  length  of  the 
haul,  and,  consequently,  to  the  number  of  scrapers  to  be  used. 
The  scrapers  travel  in  the  direction  indicated  by  the  arrows.  A 
similar  but  opposite  arrangement  can  be  used  in  excavating  a 
trench  in  which  the  materials  are  to  be  deposited  on  each  side  of 
the  cut,  as,  for  instance,  in  the  construction  of  canals  for  drainage 
or  irrigation  purposes. 

Scrapers  can  be  used  also  for  removing  materials  in  leveling 
up  the  ground  for  the  construction  of  storage-reservoirs  or  rail- 
road yards.  In  these  cases  the  work  is  directed  in  various  ways, 
depending  upon  the  conditions  of  the  locality.  The  land  to  be 
leveled  may  contain  many  isolated  knolls  which  have  to  be  cut 
down  and  the  materials  used  for  filling;  or  it  may  be  on  a  side 
hill,  and  all  the  materials  from  the  cut  employed  in  the  fill.  In 
the  former  case  the  work  may  be  arranged  in  the  way  indicated 
in  Fig.  137.  At  each  one  of  the  knolls  a  plow  may  loosen  the 
earth  and  give  work  to  scrapers,  which  will  travel  radially,  dump- 
ing the  earth  all  around  where  the  filling  is  required.  The  dia- 
gram given  in  Fig.  137  shows  an  ideal  solution  of  the  case,  but  it 
gives  a  fair  idea  of  the  work  of  scrapers  where  the  material  from 
knolls  must  be  deposited  all  around.  The  arrows  along  the  edge 
of  the  knoll  represent  the  course  of  the  plow. 

In  the  construction  of  large  yards,  in  side-hill  work  the  earth 
can  be  removed  in  the  manner  indicated  in  Fig.  138.  The  plow, 


THE   DIRECTION    OF    EXCAVATION   WORK. 


291 


trenching  back  and  forth  aloi%  the  edge  of  the  cut,  removes  the 
earth,  which  is  taken  up  by  the  scrapers  and  dumped  where  the 
filling  is  required.  The  number  of  plows  to  be  employed  depends 
upon  that  of  the  scrapers  that  have  to  be  served,  and  the  number 


FIG.  137. 


FIG.  138. 


of   scrapers,  as   has    been  remarked   above,  depends  upon   their 
capacity  and  the  distance  of  the  haul. 

Scrapers  can  be  conveniently  employed  in  transferring  mate- 
rials from  the  point  of  excavation  to  a  place  where  the  earth  is 
dumped  into  larger  and  more  efficient  vehicles  for  distant  hauling. 
In  such  a  case  a  narrow  trench  is  cut  in  the  ground  by  means  of 
plow  and  scraper.  The  trench  is  then  widened  so  as  to  allow  a 
wagon  to  easily  pass  through;  and  it  is  carried  down  to  such  a 
depth  that  when  a  platform  is  placed  across  the  trench  and  flush 
with  the  ground-surface,  it  will  not  interfere  with  the  wagons. 
The  trench,  as  indicated  in  the  longitudinal  section  of  Fig.  139, 


FIG.  139. 


is  excavated  with  a  double   inclination  converging  toward  the 
center;   one  of  the  inclines  is  steeper  for  the  descending  wagons, 


292  EARTH  AND  ROCK  EXCAVATION. 

while  one  comes  to  the  surface  at  a  smaller  inclination  to  facilitate 
the  ascent  of  loaded  wagons.  Between  the  edges  of  the  trench 
and  just  above  the  deep  portions  is  placed  a  platform  flush  with 
the  ground.  This  is  composed  of  square  beams  placed  across  the 
trench,  having  on  top  heavy  planks  running  parallel  with  the 
trench  itself.  In  the  center  of  the  platform  there  is  a  hole  3X3  ft. 
The  scrapers,  taking  up  material  around,  the  trench,  pass  over  the 
platform,  and  when  the  slot  is  reached  the  driver  dumps  them. 
A  wagon  standing  under  the  slot  receives  the  earth,  and  when 
filled,  moves  to  give  place  to  another.  Fig.  140  represents  the 


D 


FIG.  140. 

plan  of  the  trench,  and  indicates  the  course  of  the  scrapers  as 
well  as  that  of  the  wagons. 

The  New  Era  grader  is  very  convenient  for  the  construction 
of  railroads  where  the  ground  is  level,  so  that  only  a  small  em- 
bankment is  required,  formed  with  materials  excavated  from 
trenches  on  each  side  of  the  road,  which  are  to  be  used  as  drains. 
It  is  very  convenient  also  in  the  excavation  of  irrigating  canals, 
where  the  earth  is  to  be  deposited  along  the  edges  of  the  canal  to 
form  the  levees;  also  in  the  construction  of  large  reservoirs,  and 
in  leveling  the  ground  for  large  railroad  yards,  etc.  The  manner 
of  doing  the  work  in  these  various  cases  will  be  briefly  reviewed. 

In  the  construction  of  small  embankments  for  single-  or 
double-track  railroads,  the  machine  runs  over  the  trench  to  be 
excavated  at  the  left-hand  side  of  the  road.  In  advancing 
the  machine,  the  earth  removed  going  up  the  incline  (whose 
length  will  depend  upon  the  distance  from  the  trench  to  the 
center  of  the  road)  will  be  dumped  so  as  to  form  the  embank- 
ment. After  having  traveled  to  some  distance  on  one  side,  the 
machine  returns  to  the  starting-point  by  following  the  line  of 
the  trench  on  the  opposite  side  of  the  road,  and  dumping  the 
material  so  as  to  form  the  right  side  of  the  embankment.  By 
passing  several  times  along  the  same  route,  always  proceeding  a 


THE   DIRECTION    OF    EXCAVATION   WORK. 


293 


little  inward  or  outward,  this  embankment  will  be  completed 
without  the  necessity  of  employing  any  vehicle  for  the  transpor- 
tation of  the  materials. 

It  will  take  twelve  days  to  construct  embankments  16  ft.  wide 
and  3  ft.  high,  for  a  single-track  railroad,  or  28  ft.  wide  and  2  ft. 
high  for  a  double-track  road,  according  to  the  diagrams  given  in 
Fig.  141.  Assuming  the  daily  cost  of  working  of  the  New  Era 


FIG.  141. 

grader  as  $18,  as  given  by  the  manufacturers,  it  will  cost  $216  to 
build  embankments  for  one  mile  of  road  of  the  dimensions  indi- 
cated above. 

New  Era  graders  are  very  efficient  in  the  excavation  of  ditches 
and  canals  for  irrigation  purposes.     The  diagram  (Fig.  142)  in- 


Diagram 


FIG.   142. 

dicates  the  manner  of  excavating  a  ditch  29  ft.  wide  on  top,  8  ft. 
wide  at  the  bottom,  and  7  ft.  deep,  as  given  by  the  Western  Wheeled 
Scraper  Company.  The  banks  have  slopes  of  1J  to  1,  with  a  6-ft. 
berm  on  each  side,  and  the  embankments  formed  with  the  excavated 
materials  are  21^  ft.  wide  and  5J  ft.  high.  It  will  require  the 
handling  of  about  25,500  cu.  yds.  per  mile,  and  it  will  take  about 
25  days  to  finish  each  mile.  As  this  is  a  deeper  ditch  than  can 
be  cut  directly  with  this  kind  of  machine,  it  is  necessary  at  first 
to  take  out  the  section  marked  a  in  the  figure,  41  ft.  wide  and  2  ft. 


294 


EARTH   AND    ROCK    EXCAVATION. 


deep,  using  a  21-ft.  elevator,  working  each  plowing  from  the 
outside  to  the  center,  and  delivering  the  earth  on  each  bank. 
Then  narrow  the  work  down  to  23  ft.,  as  shown  by  section  b,  and 
take  out  3  ft.  with  slopes  of  1£  to  1,  working  from  the  outside  to 
the  center,  and  delivering  the  earth  on  each  bank  as  before.  Then 
the  remaining  2-ft.  section  c  is  taken  out  by  cross-firing,  working 
from  center  to  outside,  and  delivering  the  earth  on  the  opposite 
shoulder,  which  was  prepared  by  taking  out  the  first  2  ft.  The 
manner  of  handling  the  work,  by  excavating  the  earth  from  the 
left  side  of  the  ditch  and  dumping  it  on  the  right  bank,  and  vice 
versa,  is  called  cross-firing. 

The  real  cost  per  mile  for  excavating  a  ditch  of  the  dimen- 
sions given  will  be  $450.  This,  however,  does  not  include  the 
general  expenses,  superintendence,  contractors'  profit,  etc.  Fig. 


PIG.  143. 


143  gives  a  fair  idea  of  the  excavation  of  trenches  by  means  of 
the  New  Era  grader. 

In  ditches  of  larger  dimensions,  or  when  the  earth  from  the 


THE    DIRECTION    OF    EXCAVATION    WORK.  295 

cuts  must  be  used  for  fills,  the  hauling  is  done  by  means  of  dump- 
ing-wagons. The  work  shoulcTbe  arranged  so  as  to  have  always 
an  empty  wagon  at  hand  ready  to  be  filled.  As  soon  as  one  wagon 
is  loaded  an  empty  one  must  take  its  place  under  the  incline. 
The  success  of  the  work  consists  in  having  the  proper  number  of 
wagons  serving  the  machine,  and  this  number  should  be  in  pro- 
portion to  the  distance  of  haul.  To  load  1000  cu.  yds.  in  ten 
hours  a  wagon  must  be  at  the  side  of  the  machine  every  30  to  50 
seconds.  A  team  with  a  dumping-wagon  will  haul  to  a  distance 
of  90  ft.,  dump,  and  return  in  one  minute.  When  the  haul  is  not 
over  50  ft.,  four  wagons  will  attend  the  machine.  For  each  addi- 
tional 90  ft.  another  team  must  be  added. 

Fig.  144  represents    the   Western    elevating-grader,    ditcher, 


FIG.  144. 

and  wagon-loader,  a  machine  similar  to  the  New  Era  grader, 
excavating  and  loading  earth  into  wagons.  It  shows  a  wagon 
being  loaded  while  both  machine  and  wagon  are  in  motion. 

The  following  table,  indicating  the  number  of  wagons  to  be 
used,  the  total  daily  cost  of  handling  the  earth,  including  the 
cost  of  operating  the  machine  and  the  wagons  necessary  for  the 
transportation  of  the  earth,  as  well  as  the  cost  per  cubic  yard  of 
earth  removed,  is  given  by  the  F.  C.  Austin  Manufacturing  Com- 
pany, the  manufacturers  of  the  New  Era  grader.  These  estimates 


296 


EARTH    AND    ROCK    EXCAVATION. 


are  based  upon  the  cost  of  handling  on  the  level,  but  for  deep  ex- 
cavations in  large  canals  or  high  embankments,  in  constructing 
levees  or  reservoirs,  10  per  cent,  should  be  added  to  the  price  given. 
For  cutting  down  hills  where  wagons  load  heavily  for  down-hill 
haul,  10  per  cent,  can  be  deducted  from  the  price  named.  The 
wage-rate  assumed  is  $3.50  for  man  and  team. 


Length  of 
Haul, 
Feet. 

Number  of 
Wagons. 

Total  Daily 
Cost. 

Cost  per 
Cubic  Yard, 
Cents. 

140  to  320 

5 

$34.75 

3J 

410 

6 

38.25 

31 

500 

7 

41.75 

<H 

590 

8 

45.25 

4l 

680 

9 

48.75 

4   - 

950 

12 

60.25 

6 

1220 

15 

70.75 

7 

1670 

20 

88.25 

9 

1940 

23 

9S.75 

10 

2300 

27 

112.75 

m 

2600 

30 

122.25 

12} 

3000 

35 

157.25 

15rV 

In  cutting  trenches  of  small  depth,  as  well  as  in  the  excava- 
tion of  earth  from  borrow-pits,  in  which  the  materials  used  in 
the  fills  or  deposited  on  spoil-banks  must  be  transported  in  a 
direction  perpendicular  to  the  axis  of  the  construction  and  at  a 
distance  not  greater  than  90  ft.,  the  most  economical  way  of 
doing  the  work  is  to  loosen  the  earth  by  hand-tools  and  haul  the 
excavated  materials  by  means  of  wheelbarrows. 

A  distinction,  however,  should  be  made  in  the  cutting  of 
trenches  on  side-hills.  Here  the  distance  from  the  cuts  to  the 
spoil-banks  or  fills  is  so  short  that  the  excavated  materials  can 
be  easily  deposited  by  a  throw  of  the  shovel.  The  work  in  such 
a  case  does  not  afford  any  difficulty.  One  man  with  a  pick  will 
do  the  loosening,  while  another  man  with  a  shovel  will  throw 
the  excavated  materials  to  the  required  point.  Laborers  can  be 
placed  every  10  ft.,  and  even  at  a  smaller  distance  apart,  along 
the  axis  of  construction. 

In  excavating  trenches  by  hand  where  the  material  is  trans- 
ported by  means  of  wheelbarrows,  two  cases  may  happen:  either 


THE    DIRECTION    OF    EXCAVATION   WORK. 


297 


the  materials  must  be  deposited  alongside  the  edges  of  the  cuts 
in  a  direction  perpendicular  to  *  the  axis  of  the  construction,  or 
the  materials  are  used  to  make  fills  along  the  road. 

When  the  excavated  earth  is  deposited  on  spoil-banks  located 
perpendicularly  to  the  axis  of  the  road,  the  work  can  be  arranged 
in  the  manner  indicated  in  Figs.  145,  146,  and  147.  Fig.  145 
represents  the  longitudinal  profile  of  the  trench,  Fig.  146  repre- 


FIGS.  145,  146,  147. 

sents  the  plan,  the  two  other  figures  being  the  longitudinal  and 
cross-section  of  the  trench  respectively.  The  work  is  arranged 
in  the  following  manner:  The  trench  is  divided  into  sections  of 
about  100  ft.  each;  on  every  section  a  gang  of  laborers  is  em- 
ployed, acting  independently  one  gang  from  another.  Each  sec- 
tion is  separated  from  the  succeeding  one  by  means  of  a  horizon- 
tal bench  5  ft.  long,  left  so  that  two  laborers  with  wheelbarrows 
may  pass  on  this  platform  without  interference.  The  work 


298  EARTH  AND  ROCK  EXCAVATION. 

begins  with  the  excavation  of  the  soil  for  a  depth  of  1  ft.  or  1J  ft., 
and  the  material  is  deposited  in  a  direction  perpendicular  to  the 
longitudinal*  axis  of  the  trench.  But  as  the  work  progresses,  in 
order  to  reach  the  bottom  of  the  excavation,  it  is  necessary  to 
have  inclined  roads.  These  are  obtained  by  excavating  the 
ground  on  a  double  incline  from  each  platform.  The  excavation 
is  carried  down  to  a  depth  which  depends  upon  the  inclination  of 
the  road.  It  has  been  already  remarked  that  when  the  trans- 
portation of  excavated  materials  is  done  by  means  of  wheelbar- 
rows, the  inclination  of  the  road  should  not  be  greater  than  TV; 
consequently  on  100  ft.,  which  is  the  length  of  the  working  sec- 
tions, the  inclination  of  the  road  should  not  be  greater  than 
W0  =8  ft.,  or  in  other  words  on  each  road  only  a  depth  of  8  ft.  is 
reached.  When  the  ground  must  be  excavated  to  a  greater 
depth,  at  the  foot  of  the  inclined  road  is  left  another  horizontal 
bench  5  ft.  wide,  and  then  the  excavation  is  carried  down  on  an 
incline  parallel  to,  but  in  the  opposite  direction  from,  the  former 
one.  At  the  foot  of  this  second  incline  a  depth  of  16  ft.  will  be 
reached.  In  case  the  excavation  should  be  carried  to  a  still 
greater  depth,  at  the  foot  of  this  second  incline  another  5  ft.  wide 
horizontal  bench  is  left,  and  another  incline  started  with  its  direc- 
tion opposite  to  the  second  and  equal  to  the  first  of  the  inclined 
roads.  The  work  proceeds  in  this  manner  until  the  bottom  of 
the  trench  is  reached,  and  then  the  various  inclines  are  removed, 
beginning  with  the  lower  ones. 

When,  instead  of  excavating  a  trench,  an  embankment  must 
be  formed  with  the  materials  taken  from  a  borrow-pit,  the  work 
can  be  arranged  in  the  manner  indicated  in  Figs.  148,  149,  and 
150,  in  which  Fig.  149  represents  the  plan,  Fig.  148  the  longitudi- 
nal profile,  and  Fig.  150  a  cross-section  of  the  embankment  taken 
along  the  line  AB.  These  clearly  show  that  the  embankment  is 
formed  by  different  strata  of  earth  of  equal  thickness  placed  one 
above  the  other,  and  with  the  inclination  of  the  temporary  incline 
built  for  the  access  of  the  wheelbarrows,  their  horizontal  pro- 
jection is  in  the  form  of  a  trapezium.  Thus,  for  instance,  if  the 
top  of  the  embankment  has  a  width  of  30  ft.,  with  a  slope  of 


THE    DIRECTION    OF    EXCAVATION   WORK. 


299 


1  :  1J,  and  is  12  ft.  high,  the  inplines  having  a  grade  of  TV  the 
height  of  such  a  trapezium  will  be  12X12  =  144,  and  the  bases 
will  be  30  and  66  ft.  respectively.  The  stratum  in  formation  does 


FIG.  148. 


A 


FIG.  149. 


not  prevent  the  simultaneous  construction  of  other  strata  over- 
lapping each  other.  When  the  work  is  completed  the  longitudinal 
profile  of  the  top  of  the  embankment  will  be  in  the  shape  of  a 


9 

i 

FIG.  150. 

saw.  Such  an  arrangement  of  the  work,  however,  does  not  allow 
that  freedom  of  action  of  the  various  gangs  of  laborers  working 
at  the  different  strata  which  is  permitted  with  the  arrangement 
described  in  the  previous  example. 

When  the  hauling  is  done  by  means  of  wheelbarrows,  it  is 
necessary  to  arrange  the  work  in  such  a  manner  as  to  give  continu- 
ous work  to  the  men.  The  number  of  wheelbarrows  to  be  em- 
ployed must  be  such  that  a  wheeler  as  soon  as  he  arrives  at  the 
loading  place  will  find  a  wheelbarrow  already  loaded,  while  the 
shoveler  will  always  have  at  hand  a  wheelbarrow  to  load.  The 
time  employed  by  a  wheeler  to  go  a  distance,  d,  should  be  the 


300  EARTH  AND  ROCK  EXCAVATION. 

same  employed  by  the  shoveler  in  loading  a  wheelbarrow.  This 
distance  d  is  called  a  relay,  and  its  length  depends  upon  the  speed 
of  the  wheeler  and  the  capacity  of  the  barrow. 

In  a  ten-hour  day's  work  a  shoveler  may  load  20  cu.  yds.  or 
20x27=540  cu.  ft.;  the  capacity  of  wheelbarrows  being  3  cu.  ft., 
a  shoveler  will  load  180  barrows  in  a  day.  The  time  t  required 

36  000 
to  load  each  barrow  will  be      '       =200  seconds.     Now  a  man 

with  a  load  may  easily  travel  10  miles  per  day  on  horizontal  roads 
and  consequently  the  length  of  the  relay  will  be  given  by 

^  =290  ft.    and    d  =  195  ft. 

But  when  the  grade  is  ascending,  the  greater  will  be  the  effort 
and  the  smaller  the  efficiency  of  the  work  which  may  be  reduced 
to  only  two-thirds.  The  length  d  of  the  relay  will  also  be 
reduced  to  one-third,  and  will  be  130  ft. 

From  these  simple  calculations  the  number  of  men  to  be 
employed  can  be  easily  deduced,  which  is  as  many  shovelers  as 
there  are  relays  in  the  distance.  Thus,  for  instance,  if  the  earth 
should  be  dumped  300  ft.  away,  or  1J -'relays,  it  is  necessary  to 
employ  1J  wheelers  for  each  shoveler,  and  if  the  work  is  so  wide 
that  it  allows  8  men  to  work  with  the  shovel,  they,  will  provide 
continuous  work  for  12  wheelers.  If  the  earth  is  so  strong  as 
to  be  classified  as  two-man  earth,  the  number  of  laborers  re- 
quired for  the  work  will  be  4  men  at  the  pick,  8  shovelers,  and 
12  wheelers.  The  work  done  at  this  attack  can  be  assumed  at 
160  cu.  yds.  of  earth  measured  loose,  or  120  cu.  yds.  measured 
in  the  cut. 

When  the  excavation  of  the  earth  is  done  by  hand  tools  and 
the  hauling  by  wagons,  the  work  can  be  considered  under  two 
different  aspects — viz.,  the  cut  is  above  the  ground-surface  so  that 
the  cars  have  access  to  the  front  by  travelling  on  the  newly  made 
plane,  or  else  the  cut  is  below  the  ground-surface  as  in  the  excava- 
tion of  cellars  or  the  foundations  of  high  buildings  or  in  wide 
trenches  for  subways,  etc.  In  both  cases  the  work  is  very  sim- 
ple, the  only  difficulty  being  in  the  arrangement  of  the  work  so 


THE    DIRECTION    OF    EXCAVATION   WORK.  301 


as  to  employ  men  and  wagons  m  such  a  number  that  neither  the 
men  nor  the  wagons  remain  idle  for  a  single  instant.  Each  attack 
should  be  considered  independently  from  any  other,  and  on  each 
one  the  workmen  should  be  divided  into  two  gangs — one  com- 
posed of  men  with  picks  to  remove  the  earth  from  the  bank,  and 
the  second  of  shovelers  that  will  load  the  wagons.  The  success 
of  the  work  will  depend  upon  the  employment  of  the  most  con- 
venient number  of  men  and  wagons  in  the  case  considered. 

The  number  of  men  to  be  employed  in  breaking  down  the 
bank  of  earth  will  depend  upon  the  quality  of  the  soil  and  the 
height  of  the  cut.  It  should  be  directly  proportional  to  the  con- 
sistency of  the  soil,  and  inversely  proportional  to  the  height  of 
the  cut.  The  earth  is  sometimes  classified  as  one  man,  two  men, 
etc.,  which  means  that  one  man  can  remove  such  a  quantity  of 
earth  from  the  bank  as  to  give  continuous  work  to  one,  two,  three, 
etc.,  shovelers.  Or  what  is  the  same,  a  man  can  break  down  a 
quantity  of  earth  from  the  bank  in  the  same  length  of  time  that 
one,  two,  three,  etc.,  men  can  shovel  it  into  wagons. 

But  the  quantity  of  earth  removed  by  means  of  the  pick  de- 
pends also  upon  the  height  of  the  cut.  The  smaller  the  height 
the  greater  will  be  the  effort,  while  with  greater  heights  a  larger 
quantity  of  earth  can  be  battered  down,  because  the  men  can 
facilitate  the  excavation  of  the  earth  by  undercutting  the  bank 
at  first,  and  then  causing  its  fall  by  means  of  wedges  or  levers. 
In  any  case  it  will  not  take  a  long  time  and  study  to  observe  if 
the  men  employed  at  the  excavation  are  removing  from  the  bank 
the  total  quantity  of  earth  required  for  the  day's  haul. 

It  is  more  difficult  to  decide  what  is  the  most  convenient 
number  of  men  to  be  employed  for  loading  cars  at  each  attack. 
It  is  a  common  practice  among  contractors  to  employ  as  many 
shovelers  as  possible  around  the  wagons;  the  result  is  that  the 
men  often  interfere  with  one  another  and  their  work  is  not  very 
efficient.  The  writer  has  watched  very  carefully  the  loading  of 
v/agons  in  the  construction  of  the  New  York  subway  on  one  of 
the  sections  where  the  work  was  carried  on  very  successfully  and 
was  highly  praised  by  the  engineers;  12  men  were  employed  in 


302  EARTH  AND  ROCK  EXCAVATION. 

loading  a  wagon,  and  it  took  them  between  live  and  six  minutes 
to  shovel  the  earth  into  a  wagon  of  1J  cu.  yds.  capacity,  and  it 
took  nearly  two  minutes  to  have  the  loaded  wagon  leave  the  place 
and  an  empty  one  ready  for  loading.  In  the  average  7  wagons 
per  hour  were  loaded;  in  ten  hours7  work  the  12  men  could  load 
105  cu.  yds.  or  about  9  cu.  yds.  each,  which  the  writer  does  not 
consider  at  all  a  good  day's  work.  Besides  when  the  haul  is  long, 
it  is  almost  impossible  to  have  the  cars  always  at  hand  succeeding 
each  other  with  the  regularity  of  a  working  machine,  and  this 
will  still  further  reduce  the  efficiency  of  the  shovelers. 

By  shortening  the  time  for  loading  the  wagons,  the  larger  will 
be  the  quantity  of  material  hauled  in  a  day,  and  since  the  time 
for  loading  chiefly  depends  upon  the  number  of  shovelers,  it  will 
be  of  great  advantage  to  know  what  will  be  the  most  efficient 
number  of  shovelers  to  be  employed.  It  will  be  impossible  to 
give  an  answer  that  will  fit  any  case,  but  the  peculiar  conditions 
of  the  work  and  locality  should  be  carefully  examined.  In  many 
cases  the  wagon  is  placed  alongside  the  heap  of  excavated  earth 
and  then  the  number  of  shovelers  should  be  greater  on  one  side 
of  the  wagon  than  on  the  other.  As  a  rule,  if  the  men  are  too 
crowded  they  will  not  work  satisfactorily.  A  man  needs  at  least 
2  ft.  space  in  order  to  work  easily  with  ,the  shovel.  He  should 
be  placed  in  a  position  perpendicular  to  the  sides  of  the  wagon, 
whose  dimensions  are  usually  7X4  ft.,  so  that  no  more  than  4 
men  should  be  placed  along  the  longer  sides  of  the  wagon,  and  only 
2  at  the  rear.  To  allow  the  men  to  work  with  comfort,  thus  ob- 
taining the  greatest  efficiency  from  their  work,  only  10  men  should 
be  employed  in  loading  a  car  when  it  can  be  located  in  such  a 
way  as  to  be  surrounded  on  every  side  by  the  heap  of  removed 
earth.  But  in  case  the  wagon  may  be  located  so  as  to  have  the 
earth  only  along  one  side  and  at  the  rear  no  more  than  6  men 
should  be  employed. 

The  question  may  be  asked,  is  it  more  convenient  to  increase 
the  number  of  shovelers,  or  to  decrease  the  number  of  wagons? 
As  a  rule  it  can  be  said  that  the  most  economical  work  is  ob- 
tained by  employing  a  smaller  number  of  wagons  served  only  by 


THE    DIRECTION    OF    EXCAVATION   WORK.  303 

H 

few  men,  than  a  larger  numbe^of  wagons  served  by  a  crowd  of 
men,  except  in  cases  uTwhich  the  work  should  be  completed  in  a 
short  time,  and  then  the  rapidity  is  the  most  important  item  to 
be  considered  even  at  the  expense  of  economy  in  cost. 

The  number  of  wagons  to  be  employed  in  the  work  should  be 
calculated  by  taking  into  consideration  the  following  items: 

(1)  The  time  required  for  loading  the  wagons,  depending  upon 
the  number  of  shovelers  employed.     Thus  in  the  case  mentioned 
above  the  time  for  loading  the  cars  was  six  minutes,  and  consider- 
ing that  it  will  take  another  minute  to  move  the  wagon  and  get 
another  into  place,  seven  minutes  in  all  were  spent  in  loading  it. 

(2)  The  number  of  wagons  to  be  employed  depends  also  upon 
the  time  employed  in  hauling  the  load  from  the  point  of  excava- 
tion to  the  dumping-place.     The  time  employed  is  the  result  of 
the  two  elements — the  distance  of  the  haul  and  the  speed  of  the 
wagon.     The  former  varies  and  is  easily  determined  by  means 
of  one  of  the  various  methods  indicated  for  finding  out  the  mean 
distance  of  haul;  the  latter  is  generally  assumed  to  be  3  miles  per 
hour. 

(3)  The   time    required    for    unloading    the    wagon,  which  is 
usually  assumed  as  varying  between   one-quarter   and  one-half 
the  time  employed  for  loading. 

(4)  The  time  for  the  return  trip,  which  is  considered  as  equal 
to  the  time  employed  by  the  wagon  when  loaded  to  travel  the 
distance,  in  order  to  compensate  for  accidents  met  in  the  road 
and  some  unavoidable  losses  of  time. 

The  time  taken  by  items  (1)  and  (3)  is  constant,  what- 
ever the  distance  of  hauling  may  be,  while  (2)  and  (4)  depend 
upon  the  distance.  In  the  case  referred  to  above,  assuming 
the  dumping-place  located  at  3000  ft.  from  the  excavation,  it 
will  take  seven  minutes  for  loading,  twenty  minutes  to  reach  the 
waste-banks,  three  minutes  for  unloading,  and  twenty  minutes 
for  the  return  trip — fifty  minutes  all  together.  Dividing  this 
number  by  7,  the  time  employed  by  the  men  in  loading  a 
car,  we  shall  have  *f-  =  7,  the  number  of  cars  required  to  give 
continuous  work  to  the  shovelers. 


304  EARTH  AND  ROCK  EXCAVATIOX. 

In  general  the  number  of  cars  will  be  given  by  the  formula 

t  +  2T+u 
t 

in  which  £  =  time  employed  for  loading  a  wagon; 

T  =  time  employed  for  reaching  the  dump ; 
u  =  time  for  unloading  \  or  \t. 

From  this  formula  is  easily  deduced  the  great  convenience  of 
employing  dumping-wagons  which  can  be  dumped  while  the 
wagon  is  in  movement,  since  they  eliminate  one  of  the  quantities 
in  the  numerator. 

The  cost  of  the  excavation  of  the  unit  of  volume  of  the  material 
is  given  by  the  sum  of  the  different  quantities  divided  by  the 
total  amount  of  earth  hauled  in  a  day.  The  different  items  enter- 
ing into  the  calculation  are  (a)  the  cost  of  removing  the  earth 
from  the  bank,  which  is  given  by  the  wages  of  the  men  employed 
in  such  an  operation,  whose  number  depends  upon  the  consistency 
of  the  soil;  (b)  the  cost  of  shoveling  the  earth  into  the  wagons, 
given  by  the  wages  of  the  laborers,  whose  number  should  be  fixed 
by  the  engineer  according  to  the  various  conditions  of  the  locality; 
(c)  the  cost  of  the  hauling,  which  depends  upon  the  distance, 
and  (d)  the  cost  of  unloading  the  wagon. 

Considering  the  case  referred  to  above,  in  which  12  men  are 
employed  in  loading  a  wagon,  the  distance  of  hauling  being  3000 
ft.  and  the  quantity  of  earth  transported  105  cu.  yds.,  and  assum- 
ing also  that  the  wagons  employed  are  of  the  contractor's  dump 
type,  and  the  consistency  of  the  soil  is  three  men,  the  cost  of  a 
unit  of  volume  of  the  earth  excavated  and  hauled  away  will  be 
as  follows : 

4  men  at  the  cut $1.50  each=  $6.00 

12shovelers 1.50    "     =18.00 

7  wagons,  cost  of  hiring 5.00    "     =35.00 

Total  cost $59.00 

59  00 

',    =  .56,  cost  of  the  excavation  and  haul  per  cu.  yd. 

J-UO 


THE    DIRECTION   OF    EXCAVATION   WORK.  305 

% 

In  case  only  6  men  are  emj^oyed  in  loading  the  cars,  working 
easier,  they  will  shovet  not  less  than  12  cu.  yds.  per  day  each, 
or  72  cu.  yds.  in  a  ten-hour  day's  work.  They  will  spend  twelve 
minutes  in  loading  a  wagon  of  1.5  cu.  yds.  capacity,  and  for  the 
same  distance  of  3000  ft.  it  will  require  five  cars  to  give  continuous 
work  to  these  men.  The  earth  being  of  the  same  tenacity,  the 
cost  per  cubic  yard  will  be  deduced  as  follows: 

2  men  at  the  cut $1.50  each=$3.00 

6  men  at  the  shovel 1.50    "     =  9.00 

5  wagons,  cost  of  hiring 5 . 00     "     =  25 . 00 


Total  cost $37.00 

37.00 


72 


=  .51. 


By  comparing  these  two  figures  it  can  be  seen  that  there  is 
no  such  great  economy  in  increasing  the  number  of  men  for  load- 
ing a  wagon  as  is  commonly  believed;  the  only  advantage  is  in 
the  quantity  of  earth  removed  in  a  day.  When  the  bank  is  wide 
enough  to  allow  different  gangs  to  work  at  the  same  time  and 
without  interfering  with  one  another,  it  will  be  more  convenient 
to  form  gangs  of  shovelers  of  a  reasonably  small  number  of  men 
instead  of  crowding  them  around  the  wagons. 

The  manner  of  directing  the  work  when  the  cut  is  above  ground 
does  not  present  any  difficulty.  The  wagons  travel  always  at 
the  level  of  the  road  and  over  the  newly  excavated  plane,  and  go 
always  nearer  and  nearer  the  front.  To  allow  the  wagons  to  easily 
turn,  it  is  necessary  to  have  a  space  for  loading  as  wide  as  possible, 
and  it  will  be  convenient  to  divide  the  work  into  different  attacks, 
having  at  each  one  a  separate  gang  composed  of  only  a  few  men, 
instead  of  having  only  one  gang  made  up  of  a  great  many  men. 
Each  gang  should  be  provided  with  its  own  wagons,  whose  number 
should  be  in  proportion  to  the  number  of  shovelers  in  the  manner 
already  explained. 

In  case  the  cut  is  below  the  ground-surface,  as  usually  happens 
in  digging  cellars  or  wide  trenches  for  subways  or  other  purposes, 
the  work  begins  with  the  excavation  of  the  soil,  following  an  in- 


306  EARTH  AND  ROCK  EXCAVATION. 

clined  plane  with  such  a  grade  that  it  can  be  easily  overcome 
by  horses  and  wagons.  When  the  plane  of  the  excavation  has 
been  reached,  the  same  number  of  men  is  employed  in  cutting 
the  front  of  the  bank  forward,  while  the  same  gangs  of  shovelers 
will  load  the  earth  into  the  wagons  as  before.  But  other  men 
will  be  employed  in  working  in  the  opposite  direction,  cutting 
part  of  the  wide  incline  which  was  at  first  used.  In  this  manner 
only  a  portion  of  the  incline  will  remain,  and  will  be  left  of  such 
dimensions  that  it  will  afford  an  easy  passage  to  two  wagons 
going  in  opposite  directions  and  without  interfering  with  one 
another. 

This  inclined  road  is  the  last  portion  of  the  earth  to  be  cut, 
and  it  is  removed  only  after  all  the  work  of  excavation  has  been 
completed.  The  cutting  of  this  inclined  road  is  done  in  two 
different  ways,  depending  upon  the  implements  at  hand.  If  on 
the  work  there  is  a  hoisting-machine  to  be  used  afterward  in 
connection  with  derricks  or  cableways,  it  may  be  used  for  haul- 
ing the  wagons  up  the  incline.  Then  the  road  is  sliced  up  so  as 
to  make  it  steeper  with  every  slice  of  earth  taken  away,  and  the 
wagons  are  pulled  up  by  the  rope  connected  to  one  of  the  reversible 
drums  of  the  engine  and  attached  to  the  shaft  of  the  wagon. 
When  the  road  becomes  very  steep,  it  is  removed  by  cutting  it  in 
benches,  one  above  the  other,  and  2  or  3  ft.  wide  each,  and 
throwing  the  material  to  the  ground-surface,  from  where  it  is 
loaded  into  the  wagons. 

,When  there  is  no  hoisting-machine,  the  inclined  road  is  re- 
moved by  cutting  it  up  in  benches  of  different  heights.  This 
means  that  the  earth  is  cut  in  parallel  vertical  slices  and  the  mate- 
rial is  loaded  directly  into  the  wagons,  which  will  stand  on  the 
edge  of  the  cut.  With  the  progress  of  the  work  and  when  the 
cut  has  reached  such  a  height  that  this  is  no  longer  possible,  then 
the  height  of  the  cut  is  divided  into  two  benches.  The  earth 
removed  from  the  lower  bench  is  thrown  on  top  of  the  same  bench, 
where  stand  shovelers  that  throw  the  same  earth  on  the  wagons 
which  stand  on  top  of  the  upper  bench.  Recesses  of  2  or  3  ft. 
are  left  between  the  various  benches,  and  in  this  manner  the  earth 
is  shoveled  two  or  more  times  before  being  hauled  away. 


CHAPTER  XXI. 

THE  DIRECTION  OF  EXCAVATION  WORK  (CONTINUED). 

THE  manner  of  excavating  earth  by  hand-tools  and  removing 
it  by  means  of  industrial  railways  hauled  by  horses  is  convenient 
for  excavations  of  less  than  30,000  cu.  yds.  of  earth  and  for  dis- 
tances not  over  2  miles.  The  excavation  of  the  earth  from  the 
bank  is  done  in  the  same  way  as  if  the  hauling  were  done  by  means 
of  wagons.  It  is  very  important  to  have  such  a  number  of  men 
at  the  bank  as  will  cut  down  the  required  quantity  of  earth  with- 
out the  shovelers  and  cars  waiting  for  them. 

The  manner  of  arranging  the  tracks  and  how  to  form  the 
embankments  will  be  discussed  later  on.  When  the  excavation 
of  the  earth  is  obtained  by  means  of  powerful  continuous  and 
intermittent  digging-machines,  the  arrangement  of  the  tracks 
both  at  the  front  and  at  the  dumping-place  requires-  the  greatest 
attention  on  account  of  the  large  quantity  of  material  excavated 
and  dumped  in  a  day.  The  tracks  must  be  moved  continuously, 
and  yet  built  with  great  solidity,  so  as  to  stand  the  heavy  traffic 
of  the  road.  This  does  not  happen  with  industrial  railways, 
especially  when  hauled  by  horses.  Here  will  be  given  only  the 
manner  of  fixing  the  number  of  horses,  the  number  of  trains,  and 
the  number  of  cars  of  which  each  train  should  be  composed,  so  as 
to  give  continuous  work  without  any  loss  of  time;  and  also  the 
various  methods  of  cutting  the  trenches,  as  well  as  the  manner 
of  calculating  the  cost  of  the  transportation  of  the  unit  of  volume 
of  the  material. 

It  is  assumed  that  the  capacity  of  the  cars  is  1  cu.  yd.  each, 
and  the  rails  are  placed  on  horizontal  roads  or  with  an  inclination 

307 


308  EARTH  AND  ROCK  EXCAVATION. 

less  than  3  per  cent.,  and  that  the  speed  of  the  horses  in  hauling 
a  train  will  be  2J  miles  per  hour.  On  these  conditions  a  horse,  it 
is  assumed,  can  haul  five  cars. 

The  number  of  horses,  H,  required  to  haul  a  train  of  n  cars  of 
the  capacity  of  c  cu.  yds.  and  weight  w  is  given  by  the  formula 

HT=n(cm+w)(g±i), 

where  T  is  the  mean  hauling  efficiency  of  a  horse  working  ten 
hours  a  day,  m  is  the  weight  of  1  cu.  yd.  of  the  excavated  mate- 
rial, g  is  the  resistance  of  friction  of  the  rails,  and  i  the  inclination 
of  rails.  The  sign  +  is  for  the  ascending  roads,  and  the  sign  — 
when  the  road  descends  from  the  point  of  excavation  toward  the 
filling  embankment  or  dumping-place.  Nt  being  the  number  of 
trains  required  for  the  continuity  of  the  work,  is  found  in  the 
same  way  as  the  number  of  wagons  required  in  the  work  when 
the  earth  is  hauled  by  means  of  wagons.  It  is  obtained  by  divid- 
ing the  time  employed  in  the  round  trip  by  the  time  employed 
in  loading  the  train,  including  in  the  round  trip  also  the  time 
for  loading  and  unloading  the  cars,  or 


where  d  is  the  distance  of  hauling,  v  the  velocity  in  feet  per  hour, 
t  time  employed  in  loading  a  train,  ^  time  required  for  unloading 
the  train. 

The  number  of  cars  required  for  continuous  work  depends 
upon  the  volume  Q  in  cubic  yards  of  the  whole  excavation,  and 
upon  D,  the  number  of  days  in  which  the  work  should  be  done; 
also  the  number  h  of  working  hours  per  day,  upon  the  distance  d, 
the  velocity  v  of  the  hauling,  and  upon  the  time  t  and  ^  employed 
in  loading  and  unloading.  The  number  of  cars,  C,  to  be  loaded 

every  day  is  given  by  jr-,  in  which  c  represents  the  capacity  of 
each  car.  But  since.  each  car  is  loaded  several  times  a  day, 


THE    DIRECTION    OF    EXCAVATION   WORK.  309 

according  to  the  distance  of,  hauling,  the  number  of  cars  to  be 
employed  in  the  work  will  be  given  by  the  formula 


C  being  the  number  of  cars  required  in  order  to  have  continuous 
work,  the  number  of  cars  n  for  each  train  will  be  given  by 

C          Ct 


N    t    2d 
v 


Consequently  the  work  should  be  arranged  with  a  number  of 
horses, 

Q 


with  a  number  of  cars, 


with  a  number  of  trains, 

2d 


t 
and  each  train  provided  with  a  number  of  cars, 

C 

n=N' 

The  cutting  of  the  trenches  for  roads  and  railroads,  besides 
the  usual  manner  of  attacking  the  bank  at  the  front  for  the  whole 
width  of  the  trench,  can  be  made  also  in  two  different  ways,  known 
as  the  open-cut  and  the  English  method. 

The  open-cut  method  was  in  great  favor  with  engineers  and 
contractors  some  time  ago,  but  it  is  now  nearly  abandoned;  it 
is  given  here  because  in  some  particular  cases  it  may  be  found 


310 


EARTH    AND    ROCK    EXCAVATION. 


useful  even  to-day.  Figs.  151  and  152  show  the  plan  and  longi- 
tudinal section  of  a  trench.  Along  the  longitudinal  axis  of  the 
trench  is  opened  a  cut  for  the  whole  height  of  the  trench.  The 
width  of  the  cut  is  such  as  to  allow  the  passage  of  cars  and  its 

FIG.  151. 


FIG.  152. 

sides  are  left  as  vertical  as  possible.  On  the  bottom  of  this  cut, 
corresponding  to  the  plan  of  the  proposed  road,  is  laid  the  track. 
The  cut  is  widened  afterward  by  means  of  the  lateral  excavations 
marked  S2,  S3,  84,  etc.,  in  the  figure,  and  each  cut  has  its  own 
point  of  loading.  As  soon  as  the  parts  S2  are  excavated  the  track 
is  shifted  into  two  lines,  each  one  being  close  to  the  excavation, 
so  that  the  work  is  served  by  a  double- track  line  except  on 
parts  1  and  2,  where  there  is  only  a  single-track  line  for  hauling 


THE    DIRECTION    OF    EXCAVATION   WORK. 


311 


the  earth  excavated  at  partg^l  and  2.  The  congestion  of  cars 
at  the  front  prevents  all  gangs  from  working  continuously,  because 
they  have  to  stop  while  the  trains  are  manoeuvring,  and  for  this 
reason  this  method  of  cutting  trenches  is  expensive  and  slow. 

FIG.  153. 


FIG.  154. 


A  similar  method,  but  one  affording  greater  convenience,  is  the 
one  indicated  in  Figs.  153  and  154.  It  consists  in  opening  at 
first  a  narrow  trench  along  the  longitudinal  axis  of  the  cut.  On 


312  EARTH  AND  ROCK  EXCAVATION. 

the  floor  of  this  trench,  whose  depth  is  very  shallow,  is  placed  a 
single-track  line,  and  the  excavation  is  then  made  on  the  part 
marked  2  in  the  figure  and  is  carried  down  to  such  a  depth  that 
it  is  no  longer  possible  to  load  the  cars.  After  this  cut  has  been 
made  the  track  is  removed  to  the  bottom  of  excavation  No.  2, 
and  the  cars  are  loaded  with  the  earth  taken  from  the  cut  marked  3 
and  4  in  the  figure  at  the  right  and  left  of  the  track.  When  the 
excavation  of  these  two  parts  is  completed  the  track  is  lowered 
to  the  floor  of  cut  No.  3  and  the  earth  is  taken  from  parts  5  and 
6,  and  when  these  are  entirely  cut,  the  track  is  lowered  again 
to  the  bottom  of  trench  No.  5  and  the  earth  is  excavated  from 
parts  7  and  8,  etc. 

The  arrangement  of  the  tracks  along  the  longitudinal  axis 
of  the  construction  is  indicated  in  Fig.  154.  The  work  begins 
by  laying  the  track  in  Section  1  with  an  inclination  very  close 
to  the  ground-surface,  which  in  some  cases  may  be  very  steep. 
With  the  consecutive  excavations  the  inclination  of  the  road  is 
changed  until  a  convenient  one  is  obtained  for  the  cars  employed 
to  haul  the  earth.  Such  an  inclination  begins  to  be  convenient 
in  the  excavation  of  Section  5  and  the  following  until  the  floor 
of  the  trench  is  reached.  On  this  the  loaded  cars  may  easily 
slide  down  the  incline  and  perhaps  haul  up  the  empty  ones, 
or  these  can  be  otherwise  easily  hauled  up.  The  descending  of 
the  loaded  cars  along  steep  roads  is,  however,  very  dangerous, 
and  if  they  are  not  provided  with  brakes  some  means  should  be 
devised  to  prevent  their  running  away  in  the  manner  described 
in  hauling  the  material  on  inclined  roads. 

The  lowering  and  removing  of  the  track  from  one  section  to 
another  can  be  performed  in  different  ways,  depending  chiefly 
on  the  quality  of  the  soil  and  the  particular  conditions  of  the 
locality.  Thus,  in  the  case  considered  above,  after  the  corre- 
sponding cuts  have  been  made,  the  tracks  must  be  not  only  lowered, 
but  also  transferred  horizontally.  When  the  soil  is  very  loose 
or  wet  on  account  of  percolation  of  water,  the  moving  of  the  track 
is  obtained  by  means  of  several  men  working  along  the  line  and 
pushing  the  track  with  iron  bars.  The  track  will  reach  its  new 


THE    DIRECTION    OF    EXCAVATION   WORK.  313 

h 

position  by  sliding  along  the^lope  which  was  left  for  the  former 
embankment  and  upon  which  the  track  stood.  But  when  the 
soil  is  dry  and  resistent  so  that  the  sides  of  the  cut  are  nearly 
vertical,  the  track  is  lowered  arid  then  transferred  horizontally 
to  its  new  position.  In  such  a  case  the  earth  under  the  track  is 
removed  until  only  a  few  pillars  are  left  to  hold  up  the  track; 
then  props  are  inserted  and  the  pillars  of  earth  cut  down.  By 
removing  the  props  the  track  will  fall  on  the  floor  of  the  exca- 
vation, from  where  by  means  of  levers  it  can  easily  be  transferred 
to  the  required  place. 

The  arrangement  of  the  cars  at  the  point  of  excavation  must 
be  such  as  to  insure  continuous  work  both  to  the  men  and  machines, 
in  case  these  are  employed,  for  the  removal  of  the  earth.  This 
is  a  very  important  item  to  be  considered,  especially  in  works  of 
great  magnitude;  then  it  is  necessary  to  dispose  the  tracks  in 
such  a  way  that  a  train  of  empty  cars  may  immediately  take  the 
place  of  the  ones  whose  cars  have  just  been  loaded. 

When  the  work  is  in  side  hill,  as  in  the  excavation  of  the 
trench  given  in  Fig.  153,  the  simplest  arrangement  of  the  tracks  is 
that  indicated  in  Fig.  154,  where  a  track  AB  is  located  at  the  foot 
of  the  slope  and  on  the  floor  of  cut  5  where  the  men  are  working. 
At  a  short  distance  from  the  point  of  excavation  it  is  necessary 
to  have  a  side  track  for  the  service  of  the  trains.  The  empty 
train  enters  the  track  EF  and  stops  there,  while  either  the  horses 
or  the  locomotive  haul  the  loaded  train  along  the  track  AB  to  a 
point  beyond  the  switch  C  on  the  main  track.  Then  the  empty 
train  is  hauled  back  on  the  main  track  and  enters  the  track  AB, 
bringing  the  empty  train  to  the  point  of  hauling. 

In  many  cases  the  bank  is  attacked  at  several  points  along 
the  front  and  then  more  than  one  train  may  be  loaded  at  a  time. 
The  convenient  arrangement  of  the  track  is  the  one  indicated  in 
Fig.  155.  The  main  track  is  produced  as  far  as  possible,  and 
finally  it  turns  to  reach  the  bank  at  the  most  advanced  point 
where  the  train  AB  is  loaded.  Along  the  main  track  is  placed  a 
switch  with  a  side  track  EF  for  the  loading  of  another  train. 
Also  in  this  case  along  the  main  track  it  is  necessary  to  have  a 


314  EARTH  AND  ROCK  EXCAVATION. 

switch  with  a  side  track  CD  for  the  service  of  the  trains.  Such 
an  arrangement  affords  independence  to  the  trains  which  will 
be  operated  in  just  the  same  manner  as  indicated  above. 

Another  manner  of  cutting  trenches  is  according  to  the  Eng- 
lish method,  which  was  at  first  commonly  employed  in  England 
in  the  construction  of  railroads,  and  followed  afterwards  on  the 
continent,  but  is  nearly  abandoned  now.  Along  the  longitudinal 
axis  of  the  construction  and  close  to  the  floor  of  the  proposed 


FIG.  155. 

excavation  a  heading  was  excavated.  The  dimensions  of  this 
were  such  as  to  allow  the  passage  of  a  train  running  on  a  nar- 
row-gauge track.  All  along  the  line  and  just  above  the  heading 
shafts  were  sunk  and  communication  established  between  the 
ground-surface  and  the  heading.  The  shafts  were  afterwards 
enlarged  in  a  funnel-like  shape  throwing  the  material  inside  the 
shaft,  and  this  filled  the  cars  that  were  read}''  there.  The  loaded 
cars  were  removed,  and  another  train  of  empty  ones  took  their 


r/^«!?*^ 

FIG.  156.  FIG.  157. 

place  and  were  ready  to  be  filled.  In  this  manner  the  expensive 
cost  of  loading  the  cars  was  dispensed  with.  The  dimensions  of 
the  heading  were  6X7  ft.,  while  the  shafts  were  4  ft.  square. 
Other  advantages  of  this  method  are  the  rapidity  of  the  work, 
and  that  the  track  is  placed  where  it  serves  for  all  the  work  with- 
out the  necessity  of  removing  it.  Besides,  the  heading  being 
excavated  at  the  lowest  point  of  the  work,  it  served  as  a  drain. 
But  the  great  cost  of  the  excavation  of  the  heading  makes  this 
system  objectionable,  especially  when  the  cut  is  not  very  deep. 


THE    DIRECTION    OF    EXCAVATION   WORK.  315 

Figs.  156  and  157  show  the  longitudinal  profile  and  cross-section 
of  a  trench  excavation  According  to  the  English  method. 

The  cost  of  the  unit  of  volume  of  the  work  as  obtained  from 
the  working  expenses  is  deduced  from  the  following  items: 

(a)  The  cost  of  excavation. 

(b)  The  cost  of  loading  the  cars. 

(c)  The  cost  of  the  motive  power. 

(d)  The  cost  of  unloading  the  cars. 

These  are  very  easily  calculated  without  the  necessity  of  intro- 
ducing complicated  formulas  or  having  recourse  to  difficult  alge- 
braic solutions.  But  it  is  necessary  to  remember  that  the  cost 
as  given  by  these  items  is  not  the  real  one,  since  it  does  not  include 
the  interest  of  the  capital  invested  in  the  cars  and  road;  the  cost 
of  maintaining  the  road  in  good  working  order,  of  setting  up 
the  plant  at  the  beginning  of  the  work,  and  of  removing  it  after 
the  work  is  completed;  the  expenses  for  lubricating  the  cars  and 
repairing  both  the  tracks  and  cars,  and  all  the  other  expenses, 
including  the  sinking  fund.  Some  of  these  items  are  easily  de- 
duced from  the  cost  of  the  plant,  as,  for  instance,  the  interest  of 
the  capital  and  sinking  fund.  The  repairing  is  calculated  per 
annum  at  one-fourth  of  the  total  cost  of  the  cars  and  tracks,  and 
by  dividing  this  sum  by  the  total  quantity  of  earth  hauled  in  a 
year  is  found  the  quota  to  be  added  to  the  cost  of  the  unit  of 
volume  for  repairing.  The  cost  of  the  maintenance  of  the  road 
is  usually  given  by  the  wages  of  the  men  employed  for  this  pur- 
pose, and  the  cost  of  setting  up  and  removing  the  road  is  generally 
assumed  at  15  or  20  cents  per  lineal  foot. 

In  excavations  of  great  magnitude  the  earth  is  removed  by 
machine,  and  the  transportation  of  the  excavated  material  is 
usually  done  by  trains  composed  of  ordinary  railroad  cars  running 
on  standard-gauge  tracks  and  hauled  by  locomotives.  The  direc- 
tion of  the  work  in  such  a  case  is  very  difficult,  and  it  will  be 
almost  impossible  to  indicate  rules  in  regard  to  the  manner  the 
work  should  be  directed.  Every  work  can  be  done  in  different 
ways,  but  the  selection  of  the  most  convenient  in  the  peculiar 
case  the  engineer  has  to  deal  with  depends  upon  many  circum- 


316  EARTH  AND  ROCK  EXCAVATION. 

stances,  chiefly  on  the  local  conditions  of  the  work  and  the  machines 
employed.  In  any  case  the  engineer  should  do  the  work  in  the 
simplest  way  and  with  the  smallest  effort,  which  will  result  in 
obtaining  the  work  at  the  smallest  cost.  This  generally  is  accom- 
plished by  selecting  the  most  efficient  excavators;  by  a  rational 
sequence  of  the  various  cuts  required  for  opening  the  trench;  by 
the  most  convenient  and  economic  location  of  the  tracks;  by  the 
employment  of  only  the  number  of  cars  and  locomotives  strictly 
necessary  for  the  work;  by  the  proper  formation  of  trains;  by 
facilitating  the  unloading  of  the  cars  at  the  dumping-place,  and 
by  looking  to  everything,  even  to  the  smallest  details,  so  as  to 
have  the  work  run  with  the  regularity  of  a  machine. 

The  greatest  attention  should  be  devoted  to  the  selection  of 
the  most  convenient  excavating  machines  required  for  the  work. 
In  the  description  of  the  various  excavators  it  was  said  that  both 
the  continuous  and  intermittent  machines  will  dig  either  above 
or  below  the  plane  of  the  embankment  upon  which  the  machine 
stands.  With  the  exception  of  the  grabbing-bucket  excavator, 
which  is  able  to  dig  the  earth  from  any  depth,  all  the  other  machines 
excavate  the  earth  to  a  limited  height  only  so  that  when  the 
trench  to  be  cut  is  very  high,  it  is  necessary  to  cut  it  in  several 
sections  one  above  the  other.  This  will  require  the  removal  and 
lowering  of  the  trackway  several  times,  an  operation  which 
involves  heavy  expense.  In  such  a  case  it  will  be  useful  to 
employ  different  kinds  of  machines  for  the  various  sections  into 
which  the  cut  is  made.  Thus,  for  instance,  it  will  be  convenient 
to  employ  a  steam-shovel  for  cutting  the  earth  for  the  first  15  or 
20  ft.  in  height,  and  to  remove  the  material  on  trains  running  on 
tracks  laid  on  the  floor  of  the  cut.  The  steam-shovel  should  be 
followed  by  a  down-digging  machine,  either  of  the  continuous 
or  intermittent  type,  and  the  material  loaded  onto  trains  running 
on  the  track  previously  laid  on  the  floor  of  the  first  cut.  In  this 
manner  the  cost  of  removing  the  tracks  will  be  greatly  reduced, 
and  such  an  arrangement  is  liable  to  yield  fair  profits  to  the  con- 
tractors. But  it  requires  the  employment  of  different  kinds  of 
machines,  and  consequently  the  necessity  of  having  a  larger  and 


THE    DIRECTION    OF    EXCAVATION    WORK.  317 

expensive  plant,  besides  the  inconvenience  of  having  two  gangs 
of  men  operating  and  working  in  an  entirely  different  way,  and  it 
will  be  very  difficult  to  make  these  various  appliances  work  har- 
moniously, especially  if  the  trench  does  not  extend  to  a  great 
length.  All  the  advantages  and  disadvantages  should  be  care- 
fully examined,  and  selection  should  be  made  of  the  method 
which,  in  the  particular  case  the  engineer  has  to  deal  with,  will 
afford  the  greatest  advantage. 

In  regard  to  excavators,  American  engineers  have  very  little 
to  select  from,  since  the  only  excavator  commonly  employed  in 
this  country  is  the  steam-shovel.  It  is,  and  has  been,  so  exten- 
sively used  that  the  operators  have  acquired  such  an  experience 
in  its  handling  that  they  usually  obtain  results  not  very  far  from 
the  technical  efficiency  of  the  machine. 

The  sequence  of  the  cuts  in  the  trenches  as  well  as  the  arrange- 
ment of  the  tracks  for  hauling  the  materials  excavated  by  means 
of  the  steam-shovel  have  been  so  fully  discussed  by  Mr.  E.  A. 
Hermann  in  his  book,  "  Steam-shovels  and  Steam-shovel  Work," 
that  it  will  be  better  to  refer  the  reader  to  this  book  than  to  attempt 
to  give  here  an  incomplete  description  of  the  various  cases  he  has 
considered.  It  is  necessary  to  remark  that  these  are  not  the  only 
ones  encountered  in  the  work  of  excavation,  nor  is  the  indicated 
manner  of  excavating  and  hauling  the  only  one  which  may  be 
employed  in  such  a  case.  Here  only  three  cases  are  considered, 
the  widening  of  a  cut  when  the  material  is  loaded  on  the  main 
track;  second,  cutting  down  grades;  and  third,  opening  new 
trenches  for  construction  works.  All  of  them  are  deduced  from 
the  book  of  Mr.  Hermann. 

Widening  a  Cut. — The  manner  of  doing  the  work  is  clearly 
indicated  in  Fig.  158.  A  switch  is  put  on  the  main  track 
just  beyond  the  end  of  the  cut  and  far  enough  away  to  permit 
the  steam-shovel  to  load  the  cars  on  the  main  track.  Very  often 
in  the  beginning  there  is  not  much  room  for  the  machine,  and 
then  the  bank  is  at  first  attacked  by  hand-tools  and  the  earth 
removed  by  means  of  wheelbarrows.  Such  a  work  is  carried 
on  until  a  side  track  for  the  machine  can  be  placed  on  the  floor 


3l8  EARTH  AND  ROCK  EXCAVATION. 

of  the  excavation.  Through  the  switch  of  the  main  track  the 
machine  is  brought  in  front  of  the  bank  of  earth  to  be  removed 
and  is  ready  for  work.  Strings  of  ten  to  twenty  cars  are  then  drawn 
along  the  main  track  and  stopped  opposite  the  machine  for  load- 
ing. This  machine  as  it  works  advances,  and  when  it  has  reached 


FIG.  158. 

the  end  of  the  switch  it  advances  on  short  sections  of  track  generally 
4  ft.  long,  which  are  placed  in  front  of  it  and  again  taken  from 
its  rear,  when  it  has  moved  forward.  After  all  the  cars  have  been 
loaded  they  are  taken  away  for  unloading.  Sometimes  the 
steam-shovel  is  left  idle  until  the  train  returns,  which  is  a  very 
wasteful  method  of  working,  even  where  the  haul  to  the  dump 
is  short,  half  a  mile  to  two  miles.  Two  engines  and  crews  should 
be  used  for  hauls  up  to  ten  miles;  three  engines  and  crews  or 
more  for  longer  hauls,  or  where  the  traffic  on  the  main  line  is 
very  heavy  and  delays  to  the  work-trains  are  frequent,  the  mate- 
rial is  generally  utilized  in  filling  trestles,  widening  embankments 
for  side  tracks,  double  tracks,  yards,  etc.,  thereby  making  two 
improvements  at  the  same  time. 

Cutting  Down  Grades. — Suppose  that  the  grade  of  the  road 
is  to  be  lowered  in  the  manner  indicated  in  Fig.  159.  From 
a  switch  inserted  on  the  main  track  at  grade  the  machine  ad- 
vances, cutting  the  portion  marked  1  and  loading  the  cars  standing 
on  the  main  track.  As  it  cuts  it  moves  forward  on  a  track  laid 
on  the  floor  of  the  pit,  which  is  usually  2  ft.  below  the  plane  of  the 
main  track.  The  steam-shovel  cuts  its  way  and  advances  con- 
tinuously until  the  cut  has  been  made  for  the  whole  length  of 


THE    DIRECTION    OF    EXCAVATION   WORK. 


319 


the  knoll,  and  then  the  tracl^  which  in  this  case  was  built  con- 
tinuous instead  of  in^small  sections  as  before,  is  switched  to  the 
main  track.  The  machine  is  brought  back  again  on  the  main 
track  and  the  new  track  will  now  be  temporarily  used  by  the 
trains  as  main  track.  The  machine  will  begin  to  cut  No.  2, 
loading  the  materials  into  the  cars  running  on  the  temporary 


FIG.  159. 

main  track  on  the  bottom  of  pit  1.  The  cut  is  also  made  for  the 
whole  length  of  the  knoll,  and  the  track  laid  for  the  machine  will 
be  the  permanent  track  of  the  new  road.  The  machine  is  brought 
back  again,  cutting  the  portion  of  trench  No.  3,  loading  the  cars 
running  on  the  tracks  of  pit  2.  When  also  this  portion  has  been 
cut  the  slopes  are  adjusted  by  cutting  the  parts  limiting  the  top  of 
the  slope,  using  the  materials  for  the  fillings  of  the  lower  portion 
of  the  same  slope. 

Construction  Work. — In  the  construction  of  new  roads  it  is 
necessary  sometimes  to  cut  wide  and  deep  trenches,  and  the  work 
is  done  on  small  sections  at  a  time.  Suppose  we  have  to  cut  the 
trench  given  in  Fig.  160.  The  cut  will  be  made  at  different 
times  and  in  the  order  marked  in  the  figure.  The  work  begins 
with  the  excavation  of  portion  1  and  the  material  is  hauled 
away  by  cars  running  on  a  track  temporarily  placed  on  top  of 
the  surface-ground  and  close  to  the  edge  of  cut  1.  While 
the  machine  advances  cutting  its  way,  on  the  bottom  of  pit  1 
is  placed  a  track  upon  which  the  trains  will  pass  when  the  machine 
is  cutting  portion  2.  The  work  will  be  continued  in  the  same 
way,  always  building  up  a  new  track  for  the  machine,  while  the 


320 


EARTH    AND    ROCK    EXCAVATION. 


trains  will  pass  on  the  track  previously  built  for  the  machine  when 
cutting  the  preceding  portion.  The  work  is  arranged  in  several 
portions,  and  when  all  are  excavated  the  whole  trench  is  opened 
to  the  required  depth  and  dimensions.  The  success  of  the  opera- 


Proposed  new  main  track 
Ast.  temporary  loading  track 


tion  depends  upon  the  sequence  of  the  cuts  and  the  rational  arrange- 
ment and  connection  of  the  tracks. 

Difficulties,  however,  are  liable  to  be  encountered,  especially 
in  the  excavation  of  part  1,  when  cutting  knolls.  These  are  chiefly 
due  either  to  the  inclination  of  the  surface-ground  or  to  the  differ- 
ences in  depth  between  the  floor  of  the  pit  of  the  first  cut  and 
the  surrounding  surface-ground  where  the  track  for  the  removal 
of  the  material  is  located.  The  first  inconvenience  is  usually 
avoided  in  different  ways,  depending  upon  the  condition  of  the 
locality.  Sometimes  light  railroads  are  used,  either  hauled  by 
horses  or  by  ropes  in  the  manner  described  for  hauling  materials 
on  inclined  roads  when  the  slope  of  the  knoll  is  great,  or 
by  removing  the  material  from  cut  1  by  means  of  wagons. 
The  second  inconvenience  is  avoided  by  raising  the  track  upon 
which  the  machine  advances,  and  this  is  obtained  by  a  cribwork. 
After  the  excavation  of  part  1  is  completed  and  the  machine  is 
brought  back  again  so  as  to  begin  the  cut  of  portion  2,  the 
cribwork  is  removed  and  the  track  for  the  trains  will  now  rest 
on  the  floor  of  pit  1. 

The  train  must  be  formed  so  as  to  be  in  proportion  with  the 


THE    DIRECTION    OF    EXCAVATION   WORK.  321 

force  of  the  locomotive,  and  ^t  to  obtain  the  greatest  efficiency 
by  using  the  smallest  number  of  cars  possible,  without  inter- 
fering with  the  continuity  of  the  work.  If  the  total  number  of 
cars  is  such  that  they  can  be  hauled  by  only  one  locomotive, 
it  will  be  better  to  have  only  one  train.  After  loaded,  it  is 
immediately  hauled  to  the  dumping-place  and  unloaded,  return- 
ing right  away  to  the  point  of  excavation  to  be  loaded  again.  In 
many  cases,  however,  notwithstanding  it  is  possible  to  haul  all 
the  cars  in  one  train,  the  loss  of  time  will  be  so  great  that  the 
work  will  not  be  completed  at  the  appointed  time;  it  will  be  more 
convenient  to  use  two  locomotives  of  smaller  efficiency  and  form 
two  trains,  each  having  a  number  of  cars  half  of  the  total  number 
required  for  the  work.  In  this  case  the  trains  will  alternate  at 
the  excavation  and  at  the  dump,  and  the  service  of  locomotives 
must  be  arranged  in  such  a  way  that  the  stops  of  the  trains  at  the 
extreme  points  will  last  only  the  time  required  for  the  loading 
and  unloading  of  the  cars.  Otherwise,  to  compensate  for  the 
loss  of  time  without  using  another  locomotive,  it  should  be 
necessary  to  increase  the  number  of  cars,  and  this  addition  will 
tend  to  increase  the  cost  of  the  work  without  any  useful  practical 
return. 

If  the  time  —  employed  by  the  train  in  its  round  trip  is  equal 

to  the  time  t  required  for  loading  another  train,  and  equal  also 
to  the  time  ^  for  unloading  the  same  train,  it  is  necessary  to  have 

C 

three  trains,  each  one  composed  of  -5-  number  of  cars,  where  C  is 

o 

the  total  number  of  cars  required  for  the  excavation. 

The  number  of  trains  required  for  the  work  is  given  by  the 
formula 


and  each  train  will  be  composed  of  a  number  of  cars, 

Ct 


n 


322  EARTH  AND  ROCK  EXCAVATION. 

The  total  number  of  cars  to  be  employed  depends  upon  the  time 
allowed  by  the  specifications  to  complete  the  work,  and  this  will 
guide  also  the  engineer  in  ordering  the  number  of  excavators  to 
do  the  work  in  the  required  time.  The  number  of  cars  is  given 
by  the  formula 


In  regard  to  the  arrangement  of  the  tracks  to  the  dumping- 
place  for  the  formation  of  the  embankment,  it  could  be  said  that 
the  embankments  to  be  solid  and  resistent  should  be  made  of 
various  strata  as  thin  as  possible.  These  strata  should  be  as 
horizontal  as  possible,  and  they  are  constructed  in  the  following 
manner:  Beginning  at  the  point  at  grade  is  built  up  at  first  a 
narrow  embankment  as  high  as  the  first  stratum  and  formed  by 
dumping  the  cars  from  their  front  ends.  Upon  the  track  that 
is  laid  on  this  embankment  and  advanced  with  it  are  run  the 
trains  that  dump  the  material  sideways,  thus  enlarging  the  filling 
for  the  whole  width  of  the  embankment.  The  track  is  continu- 
ously moved  so  as  to  remain  always  on  the  edge  of  the  filling. 
Then  the  second  stratum  is  built  up  in  the  same  manner,  by  form- 
ing a  second  narrow  embankment  as  before  by  dumping  the  cars 
from  their  front  end  and  continuously  advancing  the  tracks,  and 
it  is  widened  in  the  same  way  by  dumping  the  earth  from  the 
sides  of  the  cars.  In  a  similar  manner  is  constructed  the  third 
stratum,  and  thus  the  surface  of  the  embankment  is  reached  if 
the  successive  strata  are  built  with  one-third  of  the  total  height  at 
a  time.  Figs.  161  and  162  show  the  longitudinal  and  cross-section 


FIG.  161.  FIG.  162. 


of  an  embankment  constructed  in  the  manner  just  explained. 
The  cross-section  indicates  also  the  most  economic  way  of  moving 
the  tracks,  which  are  shifted  from  the  left  to  the  right  in  the  first 
stratum,  in  the  opposite  direction  for  the  second,  and  as  in  the 


THE    DIRECTION    OF    EXCAVATION   WORK. 


323 


first  for  the  third,  when  the  w^ole  embankment  was  divided  into 
three  sections  built  hf  succession. 

When  the  embankment  has  a  greater  height,  it  may  be  built 
by  dumping  the  materials  at  the  front  for  the  whole  width  of  the 
embankments.  It  can  be  made  of  different  inclined  strata,  the 
first  ones  having  great  slopes,  and  the  successive  smaller,  until 
the  total  filling  has  been  made  and  the  embankment  constructed 
to  the  required  height,  and  in  the  manner  indicated  in  Fig.  163. 
Since  by  operating  in  this  way  the  material  must  be  dumped 


FIG.  163. 


at  the  front,  when  there  are  no  cars  so  constructed  it  is  necessary 
to  employ  turntables,  two  at  least,  and  they  can  be  located  as 
in  Fig.  164,  which  shows  also  the  arrangement  of  the  tracks. 


FIG.  164. 


The  main  track  is  divided  into  two  side-lines  where  run  the  loaded 
cars;  the  two  turntables  are  provided  with  short  section  of  track 
connected  with  a  third  central  track  where  the  empty  cars  are 
stalled  while  awaiting  to  be  formed  into  trains.  Only  one  turn- 
table may  be  used  for  forming  the  front  of  the  embankment, 
while  it  is  widened  by  dumping  the  materials  directly  from  the 
cars  standing  on  the  tracks.  The  arrangement  of  the  turntable 
and  tracks  in  this  case  is  accomplished  in  the  manner  indicated 
in  Figs.  165  and  166. 

These  various  methods,  although  convenient  for  narrow-gauge 
tracks,  are  not  convenient  when  the  heavy  cars  of  the  ordinary 
railroad  type  are  employed.  The  turntable  must  advance  con- 
tinuously, its  weight  increases  with  the  capacity  of  the  cars 


324 


EARTH    AND    ROCK    EXCAVATION. 


used,  and  it  must  be  removed  oftener.  Another  inconvenience 
is  that  these  heavy  turntables  must  always  remain  at  the 
most  advanced  portion  of  the  newly  built  embankment,  just 
on  top  of  the  slope  of  the  dump,  where  the  earth  is  so  loose 
that  it  can  hardly  stand  their  weight  and  is  liable  to  sink  or 
slide  down,  thus  arresting  all  the  work.  Besides,  dumping  the 
cars  in  this  way  requires  enormous  time,  owing  to  the  fact 


FIG.  166. 

that  the  cars  must  be  detached,  one  at  a  time,  brought  upon 
the  platform  and  dumped,  and  then  shifted  back  on  the  proper 
track.  These  various  operations  involve  a  great  deal  of  time 
and  expense,  because  several  men  and  horses  must  be  employed 
in  handling  the  cars  and  forming  the  trains.  Consequently  such 
a  method  of  forming  embankments  should  be  abandoned  when 
the  excavation  is  made  by  powerful  machines  and  the  earth 
is  hauled  by  ordinary  railroad-cars  running  on  standard-gauge 
tracks,  and  the  following  system  will  be  found  then  more  con- 
venient. 

Along  the  longitudinal  axis  of  the  road  is  constructed  a  trestle 
with  the  tracks  at  the  plane  of  the  top  of  the  embankment  which 
it  is  proposed  to  construct.  Upon  this  track  run  the  cars  that 
are  unloaded  by  machine,  and  the  earth  falls  below  and  around 
the  trestle  which  will  form  the  backbone  of  the  embankment. 
The  cost  of  the  construction  of  the  trestle  is  compensated  for 


THE    DIRECTION    OF    EXCAVATION   WORK.  325 

by  the  rapidity  with  which  the  embankment  can  be  constructed, 
by  not  removing  the  tracks  which  otherwise  will  be  required,  and 
because  it  allows  the  unloading  of  the  cars  by  machine. 

The  unloading  of  the  cars  of  the  ordinary  railroad  type  can 
be  done  by  hand  or  by  machine,  according  to  the  form  of  the  cars 
used  for  hauling  purposes.  The  most  commonly  employed  are 
the  gondola-  and  platform-cars  and  the  large  variety  of  dumping- 
cars  already  described. 

The  gondola-cars  alone  are  dumped  by  hand.  In  such  a 
case  the  laborers  travel  with  the  train,  a  gang  on  each  car,  the  num- 
ber of  men  in  each  gang  depending  upon  the  time  the  locomotive 
is  allowed  to  stop.  In  the  construction  of  new  embankments  it 
is  more  convenient  to  form  the  train  with  the  locomotive  at  the 
rear  pushing  the  train  instead  of  pulling  it;  but  when  the  train 
is  running  on  the  main  track,  it  is  indifferent  whether  the  loco- 
motive is  at  the  front  or  rear.  When  the  train  has  reached  the 
dumping-place  the  men  remove  the  board  at  the  side  of  the  car, 
and  thus  a  great  deal  of  material  will  fall,  while  with  shovels 
is  hastily  thrown  down  the  remainder.  The  train  thus  unloaded 
is  brought  back  to  the  excavation  to  be  loaded  again.  But  the 
cost  of  unloading  materials  by  hand  is  very  expensive,  and  it 
is  used  only  in  connection  with  excavations  of  small  quantities 
of  earth. 

The  dumping-cars  of  the  Goodwin  and  other  types  are  cer- 
tainly very  convenient  and  easihT  handled,  but  they  are  very 
expensive,  and  the  complicated  parts  forming  the  dumping  arrange- 
ment easily  get  out  of  order,  especially  when  roughly  handled,  as  it 
is  in  connection  with  the  excavation,  in  which  the  car  has  on  many 
occasions  to  stand  the  jerks  and  strains  of  the  excavators.  For 
these  reasons  the  dumping-cars  of  large  capacity  are  very  seldom 
used  in  works  of  excavation. 

Engineers  and  contractors  prefer  to  haul  the  excavated  mate- 
rials on  the  ordinary  platform-cars  used  on  railroads,  and  the 
great  advantage  of  their  employment  is  that  they  can  be  unloaded 
by  machine.  The  simplest  machine  for  unloading  trains  con- 
sists of  a  plow  of  large  dimensions  resting  on  the  platform  of  the 


326 


EARTH    AND    ROCK    EXCAVATION. 


car,  and  it  is  located  at  the  rear  end  of  the  train.  This  plow  is 
tied  to  one  end  of  a  wire  rope  whose  other  end  is  fixed  to  the  loco- 
motive. When  the  train  has  reached  the  dumping-place,  the 
locomotive  is  detached  and  slowly  moved  away  from  the  train. 
It  will  draw  the  wire  rope,  and  the  plow  will  be  pulled  to  the 
front  of  the  train;  in  passing  along  the  platform  it  will  clear  it 
of  all  the  materials,  which  will  fall  on  the  ground.  When  the 
train  has  been  thus  unloaded,  the  locomotive  will  back  up,  the 
plow  will  be  brought  to  its  former  position,  the  locomotive  attached 
again  to  the  train,  and  this  will  be  moved  to  the  point  of  excavation 
to  be  loaded  again.  Although  this  manner  of  dumping  is  very 


FIG.  167. 

simple  and  preferable  to  any  other,  yet  it  involves  a  waste  of  time 
in  the  performance  of  the  various  operations,  especially  in  de- 
taching and  moving  the  locomotive;  to  avoid  these  inconveniences, 
different  machines  have  been  devised.  The  most  convenient 
machine  used  for  unloading  the  cars  is  the  rapid  unloader,  illustrated 
in  Fig.  167,  patented  and  built  by  the  Lidgerwood  Manufacturing 
Company.  This  consists  of  a  plow  of  large  dimensions  placed  at  the 
rear  end  of  the  last  car  of  the  loaded  train  and  resting  upon  the 


THE    DIRECTION    OF    EXCAVATION   WORK.  327 

platform  of  the  car,  the  width  j)f  the  plow  being  equal  to  that  of 
the  cars.  The  plow  is  attached  to  a  wire  rope  which  is  commanded 
by  a  single-drum  reversible  engine  located  at  the  front  end  of  the 
first  car  close  to  the  locomotive.  By  putting  the  engine  into 
gear  the  drum  revolves  and  winds  the  rope  which  will  pull  the 
plow.  This,  in  sliding  upon  the  platforms  of  the  cars,  which  are 
made  continuous  by  steel  aprons,  pulls  all  the  earth  out  of  the 
car,  and  it  will  form  the  embankment.  Plows  are  made  to  dump 
either  to  the  right  or  left  side,  or  on  both  sides  simultaneously, 
and  then  they  are  provided  with  the  point  at  the  center.  To 
prevent  the  plow  from  running  out  of  the  cars  it  is  guided  by 
means  of  small  vertical  pieces  of  timber  inserted  vertically  along 
the  sides  of  the  cars  and  a  few  feet  apart.  The  locomotive  pro- 
vides the  steam  to  the  engine,  which  exerts  a  direct  pull  on  the 
cable  of  25  tons  and  draws  in  the  same  at  a  speed  of  125  ft.  per 
minute.  The  manufacturers  claim  that  the  entire  act  of  stringing 
the  cables,  fastening  them  to  the  plow,  the  train  running  a  mile 
to  the  point  of  dumping,  the  plowing  off  of  the  load,  and  the  re- 
turning to  the  point  of  starting,  requires  about  twenty  minutes. 
The  correctness  of  their  statement  has  been  proved  on  many 
occasions  on  the  works  of  the  Delaware  and  Hudson  Canal 
Company's  railroad. 


CHAPTER  XXII. 

SHRINKAGE  OF  EARTH;  COST  OF  EARTHWORK. 

IN  removing  earth  from  its  natural  bed  the  cohesion  of  its 
particles  is  destroyed  and  consequently  it  will  occupy  larger 
spaces.  Its  volume  increases  according  to  the  nature  of  the  soil, 
as  was  explained  on  p.  134.  When  the  earth  is  deposited  in 
embankments  at  first  it  remains  loose  for  some  time,  but  in  pres- 
ence of  humidity  and  under  pressure  the  particles  are  compacted 
so  as  to  resume  a  small  degree  of  cohesion.  This  produces  the 
phenomenon  of  shrinkage,  and  more  earth  is  required  in  the  em- 
bankments if  they  have  been  constructed  to  a  given  level. 

The  shrinkage  of  earth  has  been  variously  estimated  by 
different  authors.  Prof.  Johnson,  for  instance,  is  of  the  opinion 
that  earth  will  shrink  16f  per  cent.,  while  Mr.  H.  P.  Gillette  states 
that  it  will  not  shrink  more  than  2  or  3  per  cent.  It  is  a  very 
difficult  task  to  reduce  to  a  constant  coefficient  the  shrinkage  of 
earths,  since  it  depends  upon  so  many  circumstances  which  ^re 
very  variable  and  each  one  of  which  should  be  taken  into  con- 
sideration. The  principal  causes,  however,  tending  to  alter  the 
shrinkage  of  the  earths  are:  the  nature  of  the  soil,  the  condition 
of  the  weather  during  which  the  embankments  are  formed,  and 
the  manner  in  which  the  embankments  are  built. 

Soils  when  placed  in  embankments  shrink  in  a  different  way, 
according  to  their  composition.  In  general  it  can  be  said  that 
the  shrinkage  is  inversely  proportional  to  the  looseness  of  the 
soil.  The  looser  a  soil  is  in  its  natural  bed,  the  smaller  will  be  its 
shrinkage  in  the  embankment.  This  stands  to  reason.  When 
a  soil  is  loose  its  particles  are  not  very  close  together,  with  voids 

328 


SHRINKAGE    OF    EARTH;     COST    OF    EARTHWORK.  329 

between  the  particles;  and  sinfe  it  will  swell  very  little  when  re- 
moved it  will  also  shrink  very  little  when  placed  in  the  embank- 
ment. Also  in  the  case  of  a  compact  soil :  in  being  removed  many 
voids  will  be  formed  and  the  material  will  swell  greatly,  and  when 
the  earth  is  put  on  the  embankment  it  will  occupy  a  larger  volume 
than  in  the  cut,  and  it  will  shrink  greatly,  due  to  the  closing  of 
the  voids.  The  shrinkage  of  the  embankment  depends  also  upon 
the  manner  in  which  the  embankment  was  formed.  To  prevent 
shrinkage  the  embankments  should  be  made  of  thin  layers  placed 
one  above  the  other  and  the  earth  in  each  layer  should  be  well 
rammed.  In  ramming,  the  particles  of  earth  are  driven  closer 
together,  thus  leaving  a  small  number  of  voids,  and  the  shrinkage 
will  then  be  almost  insensible.  But  if  the  embankment  is  formed 
by  dumping  the  material  for  the  whole  height  of  the  embank- 
ment, numerous  voids  will  be  left  in  the  mass,  and  they  will  slowly 
be  filled  in  under  the  action  of  the  pressure  of  the  traffic  on  the 
surface  of  the  embankment,  and  also  on  account  of  the  water, 
which  will  tend  to  carry  down  the  particles  of  the  earth  so  as  to 
fill  all  the  voids.  There  is  no  doubt  that  in  such  a  case  the  shrink- 
age of  the  embankment  will  be  greater  than  if  the  embankment 
was  built  in  small  layers  one  on  top  of  the  other.  Again,  if,  in 
building  the  embankment,  the  road  upon  which  the  materials  to 
be  dumped  for  its  construction  are  hauled  is  kept  always  on  the 
same  spot  and  advanced  along  the  same  straight  line,  the  earth 
underneath  this  portion  of  the  embankment  will  be  well  pressed, 
while  at  the  sides  the  earth  will  be  looseer.  If  the  road  instead 
had  been  shifted  continuously  from  one  side  to  another  the  earth 
on  the  embankment  would  be  equally  and  uniformly  pressed 
without  the  necessity  of  ramming  it.  In  such  a  case  the  shrinkage 
of  the  embankment  will  be  very  small. 

The  shrinkage  of  earth  in  newly  constructed  embankments 
depends  also  upon  the  weather  in  which  they  were  built.  When 
constructed  in  dry  weather  they  will  shrink  more  than  if  built  in 
a  rainy  season.  In  embankments  constructed  in  presence  of 
rain  or  water,  the  filling  of  the  voids  takes  place  during  construc- 
tion, while  if  built  in  dry  weather  the  voids  are  filled  in  afterward; 


330  EARTH  AND  ROCK  EXCAVATION. 

in  the  former  case  the  embankment  will  shrink  a  little,  while  it 
will  shrink  to  a  great  extent  in  the  latter. 

For  all  these  reasons  it  seems  foolish  even  to  attempt  to  find 
out  a  constant  mathematical  coefficient  for  the  shrinkage  of 
various  embankments.  But  there  is  even  a  worse  error  that  the 
writer  has  found  very  common  in  this  country.  Many  contract- 
ors and  even  some  engineers  believe  that  the  shrinkage  of  earth 
is  the  decrease  of  volume  of  the  earth  in  the  natural  bed.  Thus 
Trautwine  says  that  when  the  earth  is  dug,  1  cu.  yd.  is  equal  to 
jj-  or  to  0.8333  cu.  yd.  in  place;  yet  when  made  into  embankment 
it  gradually  subsides,  settles,  or  shrinks  into  a  less  bulk  than  it 
occupied  before  being  dug. 

In  a  certain  town  of  a  certain  country  the  aldermen  were 
discussing  the  project  of  opening  a  large  square  as  an  improve- 
ment to  the  town;  but  they  were  bothered  by  the  cost  of  hauling 
the  excavated  earth,  since  the  dumping-place  was  at  a  great  dis- 
tance. One  of  the  aldermen  proposed  to  solve  the  problem  by 
opening  a  large  hole  in  the  center  of  the  square  and  dumping  there 
all  the  earth  to  be  excavated.  For  many  years  this  story  has 
gone  around,  amusing  the  crowds,  but  the  writer  thinks  now  that 
the  alderman  must  have  been  a  very  good  engineer.  In  fact,  if 
earth  of  the  quality  of  puddled  clay,  according  to  Trautwine, 
shrinks  25  per  cent.,  by  making  the  hole  large  enough,  the  earth 
put  back  would  have  occupied  one-quarter  less  of  the  former 
space,  and  consequently  would  have  left  room  enough  for  the 
dumping  of  that  required  for  the  square.  It  seems  ridiculous,  but 
it  is  a  matter  seriously  discussed  in  many  books. 

Shrinkage  should  not  be  calculated  in  proportion  to  the  earth 
in  the  cut  but  on  the  newly  built  embankment.  The  mistake 
arises  from  the  manner  of  calculating  earthworks  which  is  com- 
monly employed ;  that  is,  by  tolling  the  wagons  hauling  the  earth 
that  has  been  already  excavated,  and  consequently  whose  vol- 
ume had  been  increased.  It  is  no  wonder  that  in  the  embank- 
ments it  will  shrink,  according  to  the  figures  given  by  the  various 
authors. 


SHRINKAGE    OF    EARTH;    COST    OF    EARTHWORK.  331 

i 

Trautwine,  Baker,  Pattojfe,  and  many  others  give  for  the 
shrinkages  of  the  various  soils  the  following  figures: 

Sand  and  gravel 8  per  cent. 

Gravelly  clay from    8  to  10    "      " 

Earth  loam  and  sandy  loam "      10  to  12   "      " 

Puddled  clay  and  puddled  soil. . .     "     20  to  25   "      " 

Since  the  earth  in  the  embankment  will  shrink,  the  effect  is 
that  the  top  of  the  embankment  after  a  while  will  be  found  at  a 
lower  level  than  it  was  constructed.  To  have  the  road  at  a 
required  plane  it  would  be  necessary  either  to  build  the  embank- 
ment a  little  higher  than  the  proposed  level  of  the  road,  or  other- 
wise to  compress  the  earth  during  the  construction  of  the 
embankment  so  as  to  prevent  any  further  shrinkage.  In  the 
construction  of  railroads  the  embankments  are  built  a  little  higher 
than  the  proposed  plane  of  the  road.  Each  railroad  has  a  special 
set  of  tables  giving  the  increase  to  be  made  in  the  embankments 
as  an  allowance  for  the  shrinkage,  and  the  various  data  are  given 
in  proportion  to  the  various  heights  of  the  embankments  and 
according  to  the  different  materials  entering  into  their  formation. 

The  compression  of  the  earth  during  the  construction  of  the 
embankment  can  be  made  by  hand  and  by  machine.  The  tool 
used  to  ram  the  earth  by  hand  is  the  rammer.  This  consists 
of  a  heavy,  large  piece  of  wood  in  the  shape  of  a  f  rust  rum  of  a  cone 
surrounded  by  iron  bands  and  fixed  to  a  vertical  handle.  The 
weight  varies  between  20  and  25  Ibs.,  and  is  operated  by  a  man 
who  raises  it  and  lets  it  fall  on  the  earth.  When  the  strata  of 
earth  are  very  thin,  as,  for  instance,  5  or  6  ins.  thick,  they  can 
be  rammed  very  well,  and  the  cost  will  be  between  1  and  1J  cents 
per  cubic  yard,  an  item  which,  although  very  small,  assumes  fair 
proportions  in  the  construction  of  embankments  of  great  length 
and  height. 

The  compression  of  the  various  particles  of  earth  is  obtained 
also  in  a  more  economical  way  by  means  of  rollers.  These,  accord- 
ing to  size  and  weight,  can  be  divided  into  hand-rollers  and 
rollers  moved  by  horses  and  steam. 


332  EARTH  AND  ROCK  EXCAVATION. 

Hand-rollers  consist  of  an  iron  cylinder  about  2£  ft.  in  diameter 
and  provided  with  an  axle  to  which  is  attached  a  handle.  It 
is  operated  by  a  man  who  pushes  it  over  the  earth,  and  on  account 
of  its  weight  it  tends  to  compress  the  earth  and  to  fill  in  some 
of  the  voids  that  were  left  in  the  mass.  But  the  efficiency  of 
the  hand-roller  is  very  small  in  regard  both  to  the  pressure 
exerted  and  the  quantity  of  work  done  in  a  day. 

Rollers  dragged  by  horses  are  more  powerful,  and  consequently 
more  commonly  employed.  They  are  similar  to  the  hand-rollers 
except  that  they  are  of  larger  dimensions,  being  from  6  to  7  ft. 
long  and  about  3  ft.  in  diameter.  Shafts  are  attached  in  some 
way  to  the  axle  of  the  roller  so  that  it  may  be  dragged  by  one 
or  two  horses.  To  avoid  unnecessary  effort  in  the  animals  in 
meeting  obstacles  and  in  order  to  easily  overcome  them  the  roller, 
instead  of  being  made  of  only  one  iron  cylinder,  is  made  up  of 
three  or  more  disconnected  pieces.  These  rollers  are  very  effi- 
cient on  account  of  their  weight;  they  compress  the  earth  very 
well,  and  since  the  horses  dragging  the  roller  may  travel  from 
15  to  20  miles  per  day,  the  amount  of  their  work  will  be  15X5280 
X  6  =  475,200  sq.  ft.,  or  about  10  acres  of  surface  of  the  embank- 
ment when  passing  only  once  on  the  same  spot,  or  5  acres  if  passing 
twice,  and  so  on.  The  cost  of  the  work  is  given  by  the  daily  ex- 
penses of  hiring  a  team  of  horses,  including  the  wages  of  the  driver, 
which,  according  to  the  locality,  may  vary  from  $3.50  to  $5.00,  and 
dividing  this  quantity  by  the  total  amount  of  earth  compressed 
in  a  day,  given  either  in  cubic  yards,  or  in  square  yards  of  the 
surface  of  the  embankment. 

Rollers  for  compressing  the  earth  are  also  made  of  very  large 
dimensions  and  are  operated  by  steam.  Since  these  weigh  several 
tons,  it  is  dangerous  to  have  them  run  on  newly  formed  embank- 
ments, except  in  case  the  roads  have  either  city  or  national 
importance. 

The  shrinkage  of  the  earth  in  the  embankments  can  be  also 
prevented  by  wetting  well  the  earths  while  the  embankments 
are  constructed.  Especially  if  the  work  is  done  in  the  dry  season 
water  will  have  the  same  effect  as  rain.  It  will  carry  down  the 


SHRINKAGE    OF    EARTH;    COST    OF    EARTHWORK.  333 

I 

small  particles  of  material  to  jjll  in  the  voids  contained  in  the 
whole  mass.  The  smaller  the  number  of  voids  left  the  more  in- 
sensible will  be  the  shrinkage  of  the  embankment  after  it  has 
been  constructed. 

When  the  earthworks  are  nearly  completed,  the  cuts  made, 
and  the  embankments  constructed,  it  is  necessary  to  reduce  the 
bed  of  the  road  and  the  slopes  to  a  smooth  surface.  This  work 
is  usually  done  by  means  of  a  shovel,  and  all  the  projections  re- 
moved and  the  materials  used  in  filling  up  the  ruts  and  all  cavi- 
ties along  the  platform  of  the  road.  In  portions  of  the  road, 
through  trenches,  the  earth  removed  is  carried  away,  but  the 
earth  removed  for  leveling  up  the  top  of  the  embankment  is  thrown 
along  the  slope.  The  flat  form  of  the  road  is  reduced  to  a  plane 
by  beating  it  up  with  the  flattened  portion  of  the  shovel,  or  other- 
wise with  a  piece  of  plank  to  which  a  handle  is  attached.  This 
is  raised  up  and  let  fall  on  top  of  the  earth,  and  in  this  way  it  levels 
the  earth  and  reduces  it  to  a  smooth  surface.  But  the  work 
of  men  is  slow,  since  they  cannot  level  up  more  than  250  sq.  yds. 
a  day,  and  with  roads  of  great  length  this  small  item  will  amount 
to  a  great  deal  of  money.  Then  it  will  be  more  convenient  to 
grade  the  surface  of  the  roads  by  machine.  The  graders  used  are 
those  described  on  p.  103,  and  they  are  very  efficient,  and  the 
amount  of  work  that  they  can  do  in  a  day  is  easily  calculated, 
depending  upon  the  width  of  the  blade  and  the  distance  traveled 
by  the  horses  in  a  day.  The  cost  of  the  running  expenses  is 
given  by  the  cost  of  hiring  a  team  of  horses,  including  the  wages 
of  the  driver  and  the  wages  of  an  operator,  and  dividing  this 
sum  by  the  total  area  graded  in  a  day.  When  the  surface 
of  the  road  presents  several  irregularities  the  blade  not  only 
cuts,  but  carries  away  the  material  to  be  deposited  where  it  is 
needed. 

It  is  very  convenient  to  have  the  slopes  of  the  embankment 
sodded,  but  since  such  an  operation  will  be  very  expensive  it  will 
not  be  allowed  except  in  connection  with  the  construction  of  the 
highways  through  cities.  To  preserve  the  slopes  of  the  embank- 
ments it  will  be  convenient  to  dig  up  the  vegetable  ground,  and, 


334  EARTH  AND  ROCK  EXCAVATION. 

instead  of  using  it  in  the  fallings,  to  lay  it  aside  to  be  used  after- 
ward, spreading  it  again  on  the  slopes  after  the  embankments 
have  been  constructed.  This  fertile  vegetable  ground  will  be 
seeded  and  wet,  and  the  roots  of  the  plants  that  will  grow  will 
form  a  cover  to  the  slopes,  preventing  their  sliding.  Such  an 
operation  requires  two  different  kinds  of  work:  first  laying  aside 
the  vegetable  ground  and  then  spreading  this  on  the  slopes.  For 
the  first  operation  is  required  from  .2  to  .3  of  an  hour's  work  for 
each  square  yard  of  surface,  and  for  the  spreading  of  the  earth 
along  the  slopes,  from  .3  to  .45;  and,  according  to  the  quality  of 
the  soil  for  the  two  operations,  will  be  required  from  %  to  f  of 
an  hour  per  each  square  yard,  and  the  cost  of  the  two  operations 
together  will  be  from  .051  to  .075  k,  when  k  is  the  daily  wage  of 
laborers  and  they  work  ten  hours  per  day.  These  data  are  good 
for  slopes  6  ft.  high,  but  with  higher  slopes  these  quantities  should 
be  increased  one-tenth  for  every  6  ft. 

COST   OF  THE   WORK. 

The  various  implements  for  the  excavation  and  hauling  of 
the  materials,  together  with  the  elements  for  calculating  the  cost 
of  the  unit  of  volume  of  the  work,  have  been  explained  in 
the  preceding  chapters.  Before  closing  this  small  review  of 
earthworks  it  is  necessary  to  devote  a  few  words  to  the  real  cost 
of  the  work.  There  is  no  doubt  that  the  most  important  item 
to  be  considered  in  the  calculation  of  the  real  cost  of  the  work 
is  the  cost  of  excavating  and  hauling  the  unit  of  volume  of  the 
earth,  but  there  are  other  items  which  should  not  be  forgotten, 
otherwise  the  contractor  will  find  in  the  end  a  loss  where  he  had 
expected  to  receive  a  fair  profit. 

The  various  items  to  be  considered  are  as  follows: 

1st.  The  real  cost  of  the  work  done  either  by  men  or  by 
machines  and  hauled  according  to  the  various  manners  already 
explained. 

2d.  The  general  expenses,  including  superintendence,  book- 
keeping, traveling  expenses,  etc. 


SHRINKAGE    OF    EARTH;    COST   OF    EARTHWORK.  335 

t 

3d.  The  interest  of  ^the  capital  at  hand,  which  is  necessary  for 
carrying  out  the  work  with  success,  as  well  as  the  premium  for 
the  bond  given  as  guarantee  of  the  contract. 

4th.  The  accidents  which  are  liable  to  happen  to  men  and 
properties  in  the  construction  of  the  work,  and  for  which  the  con- 
tractor may  be  held  responsible. 

5th.  The  profit  of  the  contractor. 

1st.  In  nearly  every  chapter  dealing  with  the  various  methods 
of  excavating  and  hauling  the  materials  has  been  given  the  cost 
of  the  unit  of  volume  of  the  work  as  deduced  from  the  working 
expenses.  But  this  is  not  the  only  item  to  be  considered,  since, 
according  to  what  was  explained  in  speaking  of  the  work  of  the 
machines,  the  cost  of  the  unit  of  volume  of  the  work  should  be 
increased  by  some  other  quantities,  as  the  interest  of  the  capital 
invested  in  the  machine,  the  repairing,  and  the  sinking-fund. 

Thus,  for  instance,  the  cost  of  removing  the  unit  of  volume 
of  earth  by  means  of  a  steam-shovel  will  be  given  by  the  daily  run- 
ning expenses  of  the  machine  divided  by  its  efficiency.  To  this, 
however,  should  be  added  a  quota  for  repairing,  interest,  and 
sinking-fund,  obtained  by  dividing  this  sum  by  the  total  cubic 
yards  of  earth  removed  in  a  year  by  the  same  machine.  These 
items  will  only  represent  the  real  cost  of  excavating  the  earth 
by  means  of  the  steam-shovel.  In  regard  to  the  hauling  the  cost 
for  the  unit  of  volume  is  deduced  in  the  same  manner.  If  the 
earth  is  removed  by  trains  running  on  standard-gauge  tracks, 
the  unit  of  cost  is  deduced  from  the  daily  running  expenses  divided 
by  the  hauled  quantity  in  a  day.  Also,  in  this  case,  to  this  num- 
ber a  quota  should  be  added  for  the  repairing  of  the  road,  loco- 
motives, and  cars,  interest  of  the  capital  invested  in  the  railroad, 
including  all  the  rolling-stock,  besides  the  sinking-fund.  This 
quota  is  given  by  these  various  items  divided  by  the  total  quan- 
tity of  the  material  hauled  in  a  year.  These  final  items,  repre- 
senting the  cost  of  excavating  one  and  the  cost  of  hauling  the 
other,  will  give  the  real  cost  of  removing  1  cu.  yd.  of  earth  in 
the  particular  case  considered. 

The  cost  of  the  unit  of  volume  thus  obtained,  multiplied  by 


336  EARTH  AND  ROCK  EXCAVATION. 

the  total  quantity  of  the  work  as  given  by  the  calculation  of  the 
earthworks,  will  give  the  total  amount  of  cost  of  the  whole  work. 

2d.  There  are  other  expenses  which,  although  not  directly 
required  for  the  excavation,  yet  are  necessary  for  the  direction  of 
the  work  and  to  carry  on  the  contract  in  the  manner  ordered  by 
the  specifications.  These  new  expenses,  usually  known  as  general 
expenses,  are  of  different  kinds.  Some  are  required  for  the  direc- 
tion of  the  work,  and  include  all  salaries  and  wages  of  the  men 
who  are  directing  the  work;  these  are  the  engineers,  superintend- 
ents, foremen,  etc.  To  be  included  in  the  general  expenses  are 
those  required  for  the  administration,  including  timekeepers,  book- 
keepers, clerks,  watchmen,  etc.,  and  others  of  general  order,  as 
office  rent,  stationery,  correspondence,  traveling  expenses,  illu- 
mination of  trenches  if  the  work  is  done  in  the  cities  or  along 
country  roads,  etc.  Since  it  would  be  too  tedious  and  almost 
impossible  to  accurately  calculate  for  each  work  all  the  general 
expenses  according  to  the  various  items  just  mentioned,  it  is 
customary  to  lay  aside  a  sum  for  such  a  purpose.  This  quantity, 
to  be  added  to  the  cost  of  the  work  as  given  from  paragraph  1, 
is  variously  calculated  by  the  different  authors,  but  it  is  not 
greater  than  one-tenth  of  the  total  cost  previously  found. 

3d.  The  interest  of  the  capital,  which  it  is  necessary  to  have  at 
hand,  so  as  to  carry  on  the  contract  with  a  great  success,  and  the 
premium  to  be  paid  to  the  company  furnishing  the  bond,  are 
important  items  to  be  considered  in  the  calculation  of  the  real 
cost  of  the  work.  It  is  a  common  practice  for  every  party  giving 
out  contracts  to  require  bonds  from  the  contractor  as  a  guarantee 
of  the  fulfilment  of  the  conditions  imposed  upon  him  by  the  specifi- 
cations. The  total  amount  of  the  bond  should  not  be,  as  a  rule, 
greater  than  20  per  cent,  of  the  total  amount  of  the  work,  while 
the  writer  has  knowledge  of  some  contracts  in  which  were  required 
bonds  amounting  to  50  per  cent,  of  the  total  cost  of  the  work. 

4.  Excavations  are  dangerous  works,  and  notwithstanding 
all  the  precautions  which  may  be  taken  by  engineers  and  con- 
tractors, accidents  are  liable  to  happen  both  to  men  and  property. 
The  workmen  are  the  ones  that,  as  a  rule,  make  up  the  list  of 


SHRINKAGE    OF    EARTH;     COST    OF    EARTHWORK.  337 

the  victims  in  any  work,  *  being  continuously  exposed,  and  it 
is  the  duty  of  the  contractor  To  lay  aside  a  sum  for  compensating 
these  accidents,  and  such  an  amount  should  be  taken  into  con- 
sideration in  fixing  the  real  cost  of  the  work.  On  one  section 
of  the  New  York  subway  a  contractor  with  a  great  political  in- 
fluence employed  a  lawyer  so  as  to  have  him  at  hand  in  any  acci- 
dent, that  he  could  gather  evidence  in  order  to  demonstrate  to 
the  friendly  judges  that  the  accident  was  caused  exclusively 
by  the  victim,  and  the  contractor  is  only  too  generous  when  he 
refuses  to  sue  him  for  damages.  These  are  abominable  means, 
and  no  gentleman  will  have  recourse  to  them  under  any  circum- 
stances. 

In  removing  the  earth  from  its  natural  bed,  the  surrounding 
properties  are  liable  to  be  damaged  either  on  account  of  settle- 
ment of  the  ground  if  the  earth  is  loose,  or  otherwise  by  the 
explosion  when  the  soil  is  so  hard  to  require  blasting.  To 
prevent  landslides,  the  cut  of  the  earth  is  shored,  but  even 
this  does  not  arrest  the  settling  of  the  soil  when  the  soil  is 
very  loose,  especially  when  the  floor  of  the  excavation  is  lower 
than  the  foundation  of  the  houses,  as  will  happen  perhaps  in 
Philadelphia  in  the  construction  of  the  subway,  where  the  soil 
will  be  very  close  to  the  line  of  the  buildings  and  their  foundations 
are  higher  than  the  floor  of  the  subway.  Contractors  must  be 
ready  to  pay  for  these  damages,  and  consequently  it  will  be  con- 
venient to  •  lay  aside  a  sum  to  compensate  them,  and  it  should 
be  deducted  from  the  total  benefit.  The  importance  of  such 
a  sum  depends  upon  the  probabilities  of  the  damages  that  may 
occur  during  the  work.  But  in  regard  to  the  damages  there  is 
always  a  discussion  on  the  party  that  is  responsible  for  them, 
notwithstanding  what  the  specifications  call  for,  and  what  was 
agreed  to  in  the  contract.  Thus,  for  instance,  in  the  fourth 
section  of  the  subway  for  the  New  York  rapid  transit  for  the 
damages  to  the  surrounding  properties  on  account  of  the  great 
explosion  caused  by  the  wholesale  storage  of  dynamite,  as  well  as 
for  the  collapse  of  the  houses,  the  city  should  have  been  held 
responsible.  Consequently  the  contractors  in  such  a  case  were 


338  EARTH  AND  ROCK  EXCAVATION. 

too  lenient  and  too  prompt  to  shelter  the  city  engineer  at  their 
own  expense. 

5.  Another  important  item  to  be  considered  in  calculating 
the  cost  of  the  unit  of  volume  of  the  work  is  the  contractor's 
benefit.  Until  not  long  ago,  and  in  some  places  continued  still 
to-day,  in  this  country  contractors  were  only  the  agents  of  the 
corporations  for  which  the  works  were  done.  These  agents,  called 
contractors,  used  to  provide  all  the  labor  and  material  required 
for  the  work  for  a  compensation  of  5,  7,  10,  or  15  per  cent.,  accord- 
ing to  their  pull  with  the  corporation.  This  is  a  very  easy  way 
of  making  money,  and  no  wonder  that  so  many  ignorants  who 
had  the  fortune  of  obtaining  some  one  of  these  contracts  became 
very  rich,  and  were  then  and  are  still  to-day  regarded  as  great 
contractors. 

Contractors,  even  according  to  our  dictionary,  are  those  who 
bargain  for  a  specified  sum  to  execute  any  work  or  enterprise 
of  considerable  magnitude.  Contractors  are  running  risks,  must 
invest  capital  in  the  purchase  of  the  various  machines  and 
implements  for  the  execution  of  the  work,  and  spend  their  time 
and  intelligence  in  carrying  out  the  work  to  a  success,  and  con- 
sequently they  are  entitled  to  a  benefit.  It  is  a  common  practice 
to  consider  the  contractor's  benefit  at  15  per  cent,  of  the  total 
amount  of  the  work,  but  this  may  be  either  too  large  or  too  small 
according  to  the  magnitude  of  the  work.  It  will  be  too  large  a 
benefit  when  the  work  amounts  to  several  million  dollars,  and 
it  will  be  too  small  when  it  does  not  amount  but  to  a  few  thou- 
sand dollars.  Therefore,  until  a  certain  limit,  the  contractor's 
benefit  should  be  inversely  proportional  to  the  total  amount  of 
the  work. 

Mr.  Ponza,  in  his  book  "  Prontuario  di  Stima,"  in  pointing  out 
the  error  of  allowing  contractors  a  fixed  percentage  of  benefit, 
suggests  a  scale  of  benefits  varying  with  the  magnitude  of  the 
work  in  the  following  way: 


Percentage 

5 
$1,000,000 

6 
$500,000 

8 
$200,000 

10 
$50,000 

15 
$10,000 

20 
$1,000 

Ajnpunt  of  the  work.    .    . 

SHRINKAGE  OF  EARTH;  COST  OF  EARTHWORK.      339 
I 

These  figures  may  be  considered  too  small  for  American  con- 
tractors, but  the  given  percentage  remaining  fixed  and  taking 
the  numbers  representing  the  total  amount  of  the  work  ten 
times  greater  than  those  given  by  Mr.  Ponza,  will  have  a  standard 
scale  of  benefits  to  be  considered  fair  and  reasonable  by  any  con- 
tractor in  every  country. 


CHAPTER  XXIII. 

EXAMPLES  OF  LARGE  CANAL  EXCAVATION  WORKS. 

IN  the  construction  of  the  many  thousands  of  miles  of  rail- 
roads all  over  the  world,  it  has  been  necessary  to  excavate  an 
enormous  quantity  of  earth,  but  the  trenches  and  embankments 
were  so  narrow  and  the  lines  extended  to  such  a  great  length  that 
the  work  could  be  attacked  at  many  points  simultaneously. 
Besides,  the  earth  was  so  easily  handled  that  these  works  did  not 
present  any  serious  technical  difficulty.  But  earthworks  assumed 
a  great  importance  in  the  construction  of  the  large  ship-canals 
built  for  national  or  international  purposes.  These  magnificent 
works  have  been  scientifically  directed  both  in  regard  to  the  time 
and  cost,  and  they  stand  now  as  monuments  of  engineering  skill. 
Many  of  the  machines  already  described  have  been  invented  or 
improved  for  the  construction  of  these  canals,  and  in  their  excava- 
tion ordinary  earthwork  has  been  elevated  to  a  science. 

In  concluding  this  little  review  of  earthworks,  brief  descrip- 
tions of  the  Suez,  Chicago,  Manchester,  and  Panama  canals  will 
be  given  as  deduced  from  the  works  of  Patton,  Martelli  and 
Stabilini,  Hill,  and  the  volumes  of  "  Engineering "  of  London. 
The  three  former  canals  have  been  successfully  completed  and 
opened  to  traffic,  the  last  one,  after  many  financial  difficulties, 
will  be  brought  to  completion  by  the  United  States  Government. 

The  Suez  Canal,  cut  through  the  isthmus  connecting  Asia 
with  Africa,  was  constructed  in  the  years  1857-69  under  the  direc- 
tion of  Mr.  Ferdinand  De  Lesseps.  The  length  of  the  canal  is 
about  100  miles,  and  it  connects  Port  Said  on  the  Mediterranean 
with  Suez  on  the  Red  Sea.  The  route  of  the  canal  deviates  some- 
what from  a  straight  line  on  account  of  utilizing  for  over  20  miles 

340 


EXAMPLES    OF    LARGE   CANAL    EXCAVATION  WORKS.  341 

I 

the  interior  lakes,  called  th$  Bitter  Lakes.  Two  cross-sections 
were  adopted  for  the  canal;  when  it  is  excavated  through  sand 
or  clay  it  has  the  following  dimensions:  width  at  water-surface 
196  ft.,  at  bottom  72  ft.,  and  depth  26  ft.  When  the  canal  was 
dug  through  the  lakes  the  cross-section  was  327  ft.  wide  at  the 
water-surface,  72  ft.  at  the  bottom,  and  26  ft.  deep.  The  slopes 
were  2  to  1,  except  through  water  where  they  were  5  to  1. 

The  ground  in  general  was  flat  and  of  very  small  elevation, 
being  on  the  average  not  more  than  6  ft.  above  the  sea-level.  At 
three  points,  viz.,  Chalons,  Serapeum,  and  El  Guisir,  for  a  total 
length  of  20  miles  the  elevations  reached  50  and  60  ft.,  so  that 
the  cutting  of  deep  trenches  was  required. 

From  Port  Said  and  for  a  length  of  40  miles  the  land  was  very 
flat;  it  was  low  and  subjected  to  tides  and  to  the  floods  of  the 
Nile  River.  Its  elevation  was  very  close  to  the  level  of  the 
sea.  The  soil,  however,  was  compact,  being  composed  of  fine 
conglomerate  sands  and  clays.  The  excavation  of  the  canal 
through  this  low  land  was  effected  by  means  of  sea-dredges, 
which  dug  their  way  and  the  removed  material  was  deposited 
on  both  sides  to  form  the  levees  on  the  edges  of  the  canal.  This 
manner  of  excavating  canals  through  low  lands  by  dredging  has 
been  ever  since  successfully  employed  in  similar  works  of  great 
magnitude. 

In  cutting  trenches  of  great  height,  as  that  of  El  Guisir,  the 
work  at  first  was  done  by  hand  and  the  material  removed  by 
donkeys  carrying  on  their  sides  mat  baskets  filled  with  earth, 
when  it  was  not  carried  by  laborers  on  baskets  resting  on  their 
heads.  From  25,000  to  30,000  men  were  employed  at  times,  and 
at  one  place  there  were  more  than  1000  donkeys.  When  the 
forced  labor  system  yvhich  prevailed  at  the  beginning  ceased, 
the  engineers  devised  more  rapid  and  economic  schemes  for  the 
construction  of  the  canal.  To  elevate  the  material  from  the  bot- 
tom of  the  canal  to  the  levees  the  flying  wheelbarrow  was  used. 
Sometimes  it  was  a  very  convenient  device,  but  it  was  soon  aban- 
doned. Better  results  were  obtained  from  the  Couvreux  excavat- 
ing machine,  especially  constructed  by  Mr.  Couvreux  on  the 


342          .    EARTH  AND  ROCK  EXCAVATION. 

principle  of  the  sea-dredge.  It  was  a  continuous  digging-machine 
of  the  ladder  type,  excavating  the  earth  downward  by  means  of 
numerous  steel  buckets  connected  to  two  endless  chains  and 
moved  by  a  revolving  drum  of  an  engine.  The  excavated 
material  was  hauled  away  .on  trains  running  along  the  different 
planes  of  the  cuts  of  the  trench.  In  some  other  cases  the 
earth  was  hauled  away  on  cars  pulled  by  chains  moved  by  a  fixed 
engine.  The  introduction  of  these  machines  greatly  hastened 
the  completion  of  the  canal,  so  that  the  total  amount  of  the 
work  done  in  the  last  four  years  was  three  times  greater  than 
the  work  which  had  been  done  in  the  preceding  eight  years. 

The  total  amount  of  earth  excavated  was  74,000,000  cubic 
meters,  and  the  cost  of  the  canal  exceeded  $100,000,000.  Like 
any  other  great  project,  the  excavation  of  the  Suez  Canal  met  with 
great  opposition  of  various  sorts.  It  was  predicted  that  the 
canal  once  excavated  would  be  soon  filled  up  with  sand  and  silt; 
that  the  Bitter  Lakes  would  also  become  deposits  of  salt,  and  that 
no  vessel  would  risk  navigating  the  canal;  but  all  these  objections 
have  utterly  failed.  The  technical  and  even  the  worse  financial 
difficulties  of  the  enterprise  which  at  times  have  seriously  threat- 
ened the  success  of  the  operation  were  happily  overcome.  The 
large  number  of  vessels  passing  every  year  through  the  canal 
already  require  it  to  be  widened  in  order  to  meet  the  needs  of 
commerce;  the  fact  that  the  traveling  distance  to  India  has  been 
shortened  over  thirty  days  stands  now  as  the  crowning  glory  of 
the  great  genius  of  De  Lesseps. 

Another  important  engineering  work  of  more  recent  date 
than  the  Suez  Canal,  arid  which  also  involved  an  enormous  amount 
of  earth  and  rock  excavation,  was  the  Manchester  Ship  Canal, 
constructed  in  the  years  1887-1893.  The  city  of  Manchester  in 
England  is  world-famed  for  its  industries  and  has  been  so  for 
many  years  past,  since  it  was  already  renowned  for  its  industries 
during  the  reign  of  Edward  VI.  Being  an  inland  city,  it  lacked 
convenient  communication  with  the  sea  for  the  transportation 
of  both  the  raw  materials  and  products  of  the  factories,  and  since 
the  year  1822  was  felt  the  necessity  of  a  canal  in  which  could 


EXAMPLES  OF  LARGE  CANAL  EXCAVATION  WORKS.     343 
$ 

easily  pass  the  largest  vessels^  land  ing  their  cargos  in  the  heart 
of  the  city.  But,  with  the  introduction  of  railroads,  the  necessity 
of  having  easy  communication  was  satisfied  for  awhile  until  with 
the  wonderful  development  of  the  city  the  project  of  a  large  canal 
called  itself  again  to  the  attention  of  the  authorities  in  the  year 
1877.  It  was  then  carefully  studied  in  all  its  details  and  the 
work  began  on  Nov.  11,  1887. 

The  Manchester  Ship  Canal,  35J  miles  long,  begins  at  Eastham, 
near  and  opposite  Liverpool  on  the  estuary  of  the  Mersey  River 
and  ends  at  Mode  wheel  in  the  city  of  Manchester.  The  total 
length  of  the  canal  can  be  divided  into  three  sections,  the  first 
between  Eastham  and  Runcorn  following  the  left  shore  of  the 
estuary;  the  second  between  Runcorn  and  Latchford  is  a  canal, 
and  the  third  between  Latchford  and  Manchester  is  an  improve- 
ment on  the  river  Mersey.  The  minimum  depth  of  the  canal 
is  26  ft.,  and  the  width  varies;  for  the  portion  between  Manchester 
and  Barton  the  bottom  width  is  170  ft. ;  from  Barton  to  Eastham 
the  bottom  width  is  120  ft.  and  the  top  width  is  172  ft. 

The  canal  is  provided  with  several  large  locks  both  at  the 
extremes  and  along  the  line,  and  passing  through  them  the  vessels 
may  be  raised  to  a  height  of  60.5  ft.  It  is  a  splendid  example 
of  a  navigable  canal  reaching  high  elevations.  Passing  through 
a  populated  district  it  is  crossed  continuously  by  roads  and  rail- 
roads which  required  the  construction  of  numerous  drawbridges. 
The  locks,  bridges,  and  the  arrangements  for  opening  the  locks 
are  very  interesting  from  an  engineering  point  of  view,  but  do 
not  enter,  however,  into  the  limits  of  this  book,  and  simply  an 
account  of  the  excavation  of  the  canal  will  be  given  here. 

Notwithstanding  in  the  excavation  of  the  Suez  Canal  the  con- 
venience of  excavating  low  lands  by  means  of  sea-dredges  which 
cut  their  way  while  digging  the  canal  was  clearly  demonstrated, 
yet  at  Manchester  the  work  began  with  the  excavation  of  the 
earth  in  a  dry  state. .  It  was  only  in  the  year  1890,  after  a  freshet 
had  broken  the  levees  separating  the  bottom  of  the  canal  from 
the  river,  that  it  was  deemed  desirable  to  excavate  the  canal  by 
dredging.  Since  then  ten  powerful  dredges  were  employed  in 


344  EARTH  AND  ROCK  EXCAVATION. 

this  work,  one  of  them,  the  "  Manchester/'  having  a  capacity 
of  850  tons  per  hour.  Only  3,000,000  cu.  yds.  were  excavated 
by  dredging,  but  the  remaining  50,000,000  were  dug  by  continuous 
or  intermittent  excavators. 

For  the  excavation  of  the  earth  were  employed  97  excavators, 
and  the  material  was  hauled  away  by  173  locomotives  and  6300 
cars  running  on  standard-gauge  tracks  which  were  located  either 
on  the  bottom  or  alongside  the  edges  of  the  canal.  The  principal 
machines  employed  were  of  two  different  types,  the  steam-shovel f 
or  navvy  and  the  continuous  down-digging  machine. 

The  steam-shovels  employed  were  of  different  patterns  and 
sizes.  The  Dunbar  &  Burton  navvy,  illustrated  on  p.  122,  was 
the  most  extensively  employed  machine  in  this  work.  Its  effi- 
ciency was  to  excavate  and  load  about  1000  cu.  yds.  of  earth 
per  day  at  a  cost  varying  between  $18  and  $20,  including  the 
wages  of  a  crew  of  12  or  14  men  for  the  service  of  the  machine 
and  tracks.  The  cost  of  this  machine  was  $5500.  Another  type 
of  steam-shovel  employed  in  the  construction  of  the  canal  was 
the  Wilson,  which,  although  much  lighter  than  the  Dunbar  & 
Burton,  offered  some  advantages  on  account  of  being  mounted 
as  a  locomotive  crane,  and,  consequently,  it  could  swing  to  a  full 
circle,  excavating  the  earth  in  every  direction.  Its  capacity  in 
a  very  loose  soil  amounted  to  600  cu.  yds.  per  day  at  a  cost  of 
$18,  including  the  wages  of  a  crew  of  14  men.  Among  the  steam- 
shovels  should  be  mentioned  the  Whitaker  intermittent  exca* 
vator,  which  was  more  economical  than  the  two  previous  types, 
since  its  cost  was  only  $4000,  but  the  capacity  of  the  machine 
was  somewhat  less;  it  could  not  excavate  more  than  500  cu.  yds. 
of  earth  per  day.  The  great  advantage  of  this  machine  was  that 
it  could  work  at  will  as  a  crane  or  an  excavator,  since  the  digging 
apparatus  consisted  of  a  grabbing-bucket  which  could  be  easily 
applied  and  removed. 

More  powerful  than  the  steam-shovel,  or  grabbing-bucket 
apparatus  were  the  continuous  digging-machines.  These  were 
of  two  different  patterns,  the  French  and  the  German.  The 
downward  continuous  excavators,  of  French  construction,  were 


EXAMPLES  OF  LARGE  CANAL  EXCAVATION  WORKS.     345 
I 

built  on  the  same  principle  as  t£ie  Satre  machine,  illustrated  on 
p.  107.  The  greatest  efficiency  obtained  from  this  machine  was 
2236  cu.  yds.  in  a  ten-hour  day's  work,  while  the  average  quantity 
of  earth  excavated  was  1490  cu.  yds.  per  day  at  a  cost  of  only 
$15.  The  excavator  of  the  German  type,  built  by  the  Liibecker 
Machinenbau  Gesellschaft  of  Liibeck,  Germany,  was  similar  to 
the  one  of  French  construction,  the  only  difference  being  that  the 
roof  covering  the  engine  and  boiler  was  very  wide.  The  machine 
stands  on  three  rails,  leaving  in  the  center  room  enough  for  the 
track  of  the  cars  which  are  loaded  with  the  excavated  materials. 
Such  an  arrangement  increases  the  solidity  of  the  machine  at 
work  and  it  is  handled  easier,  although  its  weight  was  only  70  tons, 
while  that  of  French  construction  was  80  tons.  The  capacity  of 
the  German  down-digging  machine  was  1400  cu.  yds.  per  day 
at  a  cost  of  $15. 

Another  important  engineering  work  constructed  in  the  last 
few  years,  which  necessitated  the  excavation  of  a  very  large  quan- 
tity of  earth  and  rock,  was  the  Chicago  Drainage  Canal.  The 
city  was  drained  by  the  narrow  stream  known  as  Chicago 
River,  which  emptied  into  Lake  Michigan.  With  the  increased 
population  of  the  city  the  quantity  of  sewage  increased,  and  the 
Chicago  River  became  soon  a  center  of  infection.  Since  the  water 
of  Lake  Michigan  was  used  as  the  only  supply  for  the  city,  it 
was  deemed  too  dangerous  to  have  the  lake  continue  to  perform 
the  double  duties  of  providing  the  pure  water  and  receiving  the 
sewage.  Long  ago  it  was  found  convenient  to  lift  the  water 
of  the  Chicago  River  and  convey  it  into  the  Illinois  and  Michigan 
Canal,  from  where  it  found  its  way  into  the  rivers  beyond  and 
ultimately  into  the  Mississippi.  But  during  freshets,  when  the 
floods  disarranged  the  lifting-machines,  the  danger  remained  just 
the  same  as  before.  To  solve  the  problem  in  a  permanent  way 
it  was  proposed  to  open  a  large  canal  connecting  Lake  Michi- 
gan with  the  Illinois  River,  and  to  construct  the  canal  of  such 
dimensions  as  to  be  used  not  only  for  drainage  purposes  but  also 
for  navigation  after  the  necessary  connections  were  made.  This 
canal  has  assumed  a  national  importance,  since  it  is  a  part  of  the 


346  EARTH  AND  ROCK  EXCAVATION. 

great  waterway  connecting  the  Great  Lakes  of  America  with  the 
Mississippi  River  and  by  it  with  the  Gulf  of  Mexico — a  waterway 
which  will  revolutionize  perhaps  American  commerce,  especially 
after  the  opening  of  the  interoceanic  Panama  Canal. 

The  canal  is  28  miles  long  between  the  south  branch  of  the 
Chicago  River  near  Robey  Street  to  Lockport,  and  it  runs  almost 
in  a  straight  line.  The  cross-section  adopted  was  of  two  different 
types,  varying  with  the  quality  of  the  soil  through  which  it  was 
excavated.  When  rock  was  encountered  the  cross-section  was 
practically  a  rectangle  160  ft.  wide  at  the  bottom,  162  ft.  wide 
on  top,  and  22  ft.  deep.  When,  instead,  the  canal  was  cut  through 
loose  soil,  a  trapezoidal  cross-section  was  adopted,  having  a  bottom 
width  of  202  ft.  and  side-slopes  both  above  and  below  the  water- 
surface  of  2  to  1.  The  depth  of  low  water  was  kept  at  22  ft.,  and 
the  canal  had  a  given  inclination  of  1  in  40,000,  corresponding 
to  the  flowing  velocity  of  water  of  nearly  2  ft.  per  second  through 
earth,  and  a  fall  of  1  in  20,000,  corresponding  to  a  velocity  of 
water  of  nearly  3  ft.  per  second  through  rock. 

Nearly  40,000,000  cu.  yds.  of  materials  were  excavated,  of 
which  12,330,000  were  rock  and  27,642,000  earth.  But  the  exca- 
vation proper  did  not  present  any  technical  difficulty  on  account 
of  being  only  35  ft.  deep  on  the  average,  and  the  excavated 
materials  were  deposited  in  spoil-banks  alongside  the  edges  of 
the  canal.  The  work  was  divided  into  28  sections  of  about  1  mile 
each,  and  the  work  was  done  by  different  contractors,  who  em- 
ployed different  machines,  both  for  excavation  and  hauling  pur- 
poses, some  of  which  were  especially  designed  and  constructed  for 
this  work,  while  others  were  here  applied  for  the  first  time  in 
public  works.  The  work  on  the  canal  began  in  July,  1892,  and 
was  completed  in  the  year  1897, 

The  great  importance  that  machines  had  in  the  construction 
of  the  canal  can  be  easily  deduced  from  the  fact  that  at  a  period 
of  usual  activity  the  amount  of  plant  employed  along  the  line 
was  considered  to  be  as  follows: 


EXAMPLES    OF    LAKGE    CANAL   EXCAVATION   WORKS.  347 

Steam-shovels 33 

Steam-  or  air-pumps 85 

11    "  drills 243 

"    (t  hoists 75 

Channelers 88 

Air-compressors 15 

Locomotives , 27 

Cars 900 

Dredges 27 

Grading-machines 10 

Steamboats 5 

Dump-scows 17 

Conveyors 62 

Many  of  the  machines  described  in  other  parts  of  this  book 
have  been  employed  or  specially  constructed  for  this  work.  In 
the  excavation  through  rock  the  channeling-machine,  which  had 
been  used  until  then  for  quarrying  purposes,  was  successfully  used 
here  and  was  for  the  first  time  employed  in  public  works.  For 
the  excavation  of  earth  the  Vivian  scraper  was  especially  designed 
in  order  to  excavate  the  earth  with  a  simple  and  powerful  device, 
utilizing  the  numerous  cableways  that  were  extensively  used  for 
hauling  purposes. 

On  account  of  the  favorable  conditions  of  the  work,  which  the 
material  excavated  in  the  bottom  of  the  canal  was  deposited  on 
the  waste-banks  alongside  its  edges,  it  was  found  convenient  to 
employ  different  machines  for  hoisting  and  conveying  the  earths. 
These  were  of  three  different  types — the  steel  derricks,  the  cable- 
ways,  and  the  cantilever  conveyors.  Messrs.  Smith  and  Eastman 
of  Chicago,  contractors  for  Section  14,  employed  derricks,  some 
of  them  being  fixed;  others,  instead,  were  of  the  traveling  type. 
The  latter  were  built  on  a  platform  resting  on  a  turntable,  the 
whole  being  carried  on  a  shifting  track.  The  engine  and  boiler 
were  located  on  the  platform.  The  mast  was  100  ft.  high,  and 
two  booms  were  employed  on  each  derrick  whose  length  was 
164  ft.  and  155  ft.  respectively.  Both  the  booms  and  the  mast 


348  EARTH  AND  ROCK  EXCAVATION. 

were  of  steel  reinforced  with  crosspieces  and  wire  ropes.  The 
hoisting-engine  was  provided  with  four  drums,  two  for  each  boom, 
the  arrangement  being  such  that  each  boom  handled  two  skips- 
one  depending  from  the  end,  and  the  other  at  some  distance  from 
it.  The  tackle  was  cleverly  arranged,  so  that  all  the  operations  of 
lowering  to  the  canal-bed  and  hoisting  and  tipping  the  skip 
were  performed  by  the  engineer  and  in  a  regular  sequence.  The 
operation  was  continuous,  because  when  two  of  the  skips  from 
one  boom  were  being  loaded,  the  others  on  the  opposite  boom 
were  being  discharged,  and  on  its  being  swung  round,  the 
operations  were  reversed.  The  derricks  were  placed  in  pairs  on 
opposite  banks  in  such  a  way  as  to  command  the  whole  width  of 
the  working  section.  From  120  to  450  cu.  yds.  of  earth  were 
handled  with  these  derricks  in  a  ten-hour  day's  work. 

The  Lidgerwood  movable  cableways  were  the  hoisting-  and 
convey  ing-machines  extensively  used  in  the  construction  of  the 
Chicago  Drainage  Canal.  It  was  in  this  work  that  the  movable 
cableways  were  employed,  and  they  have  fully  demonstrated  that 
they  are  very  valuable  machines  in  the  excavation  of  large  canals. 
The  tail-tower  was  mounted  on  a  car  running  along  the  edge  of 
the  canal,  while  the  tracks  for  the  head-tower  were  placed  behind 
the  waste-bank.  Since  the  total  depth  of  the  excavation  of  the 
canal  was  divided  into  three  benches  following  each  other  at 
some  distance,  so  each  front  was  served  by  a  cableway,  and  con- 
sequently they  worked  in  batteries  of  three  cableways  each. 
In  connection  with  the  movable  cableways  was  devised  the 
aerial  dump  which  was  invented  by  Mr.  Charles  Locker  and  which 
is  already  described  on  p.  239. 

The  cantilever  conveyors  used  for  hoisting  and  conveying 
the  materials  from  the  bottom  of  the  canal  to  the  spoil-banks 
were  the  Brown  machines  described  on  p.  205.  The  tracks  upon 
which  were  running  the  platforms  supporting  the  tower  to  which 
the  cantilever  was  fixed  were  placed  near  the  edge  of  the  canal. 
The  Brown  conveyors  were  working  in  batteries  in  the  same  way 
as  the  movable  cableways,  each  one  of  them  serving  the  work 
of  one  bench,  and  they  were  moved  as  the  work  advanced. 


EXAMPLES    OF    LARGE    CANAL    EXCAVATION    WORKS.  349 

Mr.  Patton  says  that  there*  has  been  considerable  competition 
between  the  manufacturers  of  the  two  machines.  It  was  admitted 
that  the  cantilever  was  capable  of  handling  a  greater  quantity  of 
material  in  a  day,  but  owing  to  its  greater  cost  it  was  claimed 
that  the  cable  ways  handle  the  materials  more  economically. 

The  interoceanic  canal  of  Panama,  still  under  construction 
through  the  narrow  isthmus  which  divides  South  from  Central 
America,  has  presented  so  many  difficulties  that  the  work  has 
been  abandoned  many  times  and  many  times  taken  up  again. 
After  it  brought  financial  ruin  to  thousands  of  families,  sorrows 
to  the  promoters  and  engineers,  and  caused  a  scandal  in  which 
were  involved  the  most  prominent  men  of  France  at  that  time, 
its  success  is  now  assured,  since  it  will  be  completed  by  the  United 
States  Government.  All  the  trouble  caused  by  the  failure  of  the 
enterprise  has  been  wrongly  attributed  to  Mr.  De  Lesseps,  who 
acted  perhaps  in  too  good  faith,  relying  on  unworthy  men,  and  was 
misled  arid  robbed  by  politicians.  But  it  cannot  be  said  that  he 
underestimated  the  magnitude  of  the  work,  that  no  preliminary 
survey  was  made  before  the  work  began,  and  that  he  did  not 
accurately  study  the  particular  conditions  of  the  work,  espe- 
cially in  regard  to  the  disposal  of  water  during  the  rainy  seasons. 
The  financial  failure  was  chiefly  due  to  the  enormous  prices  paid  in 
salaries  and  wages,  especially  at  the  beginning  of  the  work,  to 
the  costly  and  high-priced  plant  required  for  the  work,  and  to 
the  floods  which,  during  the  rainy  season,  often  in  an  hour 
destroyed  the  work  of  many  months  and  worth  millions  of  dollars. 

As  usually  happens  in  any  other  great  enterprise,  also  the 
Panama  Canal  as  projected  by  De  Lesseps  was  severely  criticized 
by  many  engineers.  When,  after  hundreds  of  millions  of  dollars 
were  spent,  it  was  realized  that  the  work  was  still  far  from  being 
completed,  people  began  to  listen  to  the  critics  and  the  original 
plans  were  modified.  Mr.  De  Lesseps,  following  the  advice  of  an 
International  Committee  which  met  in  Paris  in  the  year  1878,  pro- 
posed to  build  an  open  sea-level  canal,  in  which  the  steamers  from 
one  ocean  could  go  through  and  enter  the  other  ocean  without 
the  necessity  of '  stopping  or  being  lifted  in  their  course.  The 


350  EARTH  AND  ROCK  EXCAVATION. 

plans  were  afterward  modified  so  as  to  have  a  high,  level  canal 
with  a  series  of  locks.  Such  a  change  was  suggested  in  order  to 
greatly  reduce  the  enormous  quantity  of  excavation  which  still 
remained  to  be  done  for  the  construction  of  the  sea-level  canal. 
This  method  was  adopted  as  a  scheme  to  complete  the  canal  with 
the  limited  means  upon  which  the  company  could  rely,  espe- 
cially after  the  great  financial  troubles  in  which  it  had  been  in- 
volved. For  so  many  years  the  work  has  proceeded  slowly  along 
this  line.  But  now  that  the  United  States  Government  will 
complete  the  canal,  it  will  be  convenient  to  broadly  discuss  the 
question  of  the  superiority  of  the  high-level  over  the  sea-level 
canal.  A  few  million  dollars  more  or  less  does  not  make  any 
difference  with  the  United  States  Government,  and  now  that  the 
cost  of  the  canal  is  only  a  question  of  secondary  importance,  it 
will  be  convenient  to  take  up  again  the  question  and  see  how 
wrong  were  Lesseps  and  the  members  of  the  International  Com- 
mittee who  recommended  a  sea-level  canal. 

According  to  the  original  project,  which  the  writer  hopes  that 
the  United  States  Government  will  examine  again  before  proceed- 
ing with  the  work,  the  canal  was  43.54  miles  long,  including  2.48 
miles  of  breakwater  and  approaches  and  46  miles  of  inland  canal. 
It  begins  in  Simon's  Bay  near  the  city  of  Colon  or  Aspinwall  on 
the  Atlantic  Ocean  and  ends  near  the  city  of  Panama  on  the 
Pacific.  The  minimum  distance  between  these  two  cities  is  only 
•60  kilometers,  but  the  canal  was  projected  with  a  longer  route 
in  order  to  take  advantage  of  the  two  rivers,  the  Chagres  and  Rio 
'Grande,  which  descend  toward  the  two  oceans  from  the  ridge 
•of  mountains  which  run  along  the  isthmus  and  in  a  direction  per- 
pendicular to  the  proposed  line  of  the  canal.  The  International 
Committee  fixed  the  depth  of  the  canal  at  27.8  ft.  with  a  bottom 
width  of  72  ft.,  the  slopes  being  fixed  according  to  the  quality 
of  the  soil  encountered,  but  the  width  at  the  top  of  the  water 
was  to  be  131  ft. 

The  work  was  divided  into  five  sections,  whose  lengths  and 
amount  of  material  to  be  excavated  are  given  in  the  following 
table: 


EXAMPLES    OF   LARGE    CANAL    EXCAVATION   WORKS. 


351 


Number. 

• 

it 

Length  in 

Miles. 

Quantity  of 
Cubic  Yards. 

1 
2 

3 
4 
5 

16.33 
10.95 
6.00 
2.10 
8.16 

32,500,000 
31,200,000 
58,500,000 
35,100,000 
18,200,000 

175,500,000 

The  first  section  begins  at  the  extreme  of  the  canal  on  the 
Atlantic  Ocean  near  the  city  of  Colon,  and  follows  the  northern 
shores  of  Simon's  Bay  for  nearly  3.1  miles.  This  portion  of 
the  canal  is  cut  through  low  marshy  lands,  chiefly  composed  of 
sand;  its  height  varies  from  3  to  6  ft.  above  sea-level.  Then  the 
canal  turns  westward  toward  the  interior  following  the  valley 
of  the  Chagres  River  whose  course  often  intersects.  For  all  the 
length  of  this  section  the  land  remains  very  low,  and  toward  the 
interior  the  soil  was  found  composed  of  loam,  with  the  exception 
of  three  small  portions  in  which  rock  was  encountered.  The 
rock  was  excavated  by  blasting,  while  nearly  all  the  excavation 
in  this  section  was  effected  by  dredging.  Dredges  of  different 
types  were  employed,  and  their  efficiency  varied  from  5000  to 
9000  cu.  yds.  per  day.  On  account  of  the  awful  conditions  of 
the  climate,  which  prevented  continuous  work,  the  work  obtained 
from  the  dredges  never  amounted  to  more  than  4000  cu.  yds. 
per  day.  The  work  in  this  section  has  been  completed  long  ago. 

The  second  section  of  the  canal,  10.95  miles  long,  passes 
through  lands  which  slightly  increase  in  elevation.  It  begins  at 
nearly  40  ft.  above  the  level  of  the  sea,  and  reaches  a  height  of 
145  ft.  near  the  end  of  this  section.  The  soil  encountered  is  very 
resistent  and  compact,  but  it  was  easily  excavated  by  the  inter- 
mittent digging-machines  of  the  steam-shovel  type.  Those  em- 
ployed in  this  section  were  of  the  Dunbar-Burton  pattern,  illus- 
trated at  p.  122,  and  the  usual  American  Steam-shovel  built  by 
the  Osgood  Dredge  Co.  of  Albany,  N.  Y.  All  together  19  machines 
were  employed  in  this  section,  and  the  total  amount  of  work  ob- 
tained by  them  was  130,000  cu.  yds.  per  month. 


352  EARTH  AND  ROCK  EXCAVATION. 

The  third  section,  only  6  miles  long,  requires  a  total  excavation 
of  58,000,000  cu.  yds.,  and  it  necessitated  the  cutting  of  the  Obispo 
and  Emperador  elevations  with  trenches  250  ft.  deep.  The  Obispo 
hill  is  composed  almost  entirely  of  hard  rock,  alternated  with 
strata  of  disintegrated  rock.  These  strata  of  loose  soil  below  the 
rock  often  caused  the  sliding  of  the  surface  soil,  badly  disarranging 
the  work  and  producing  accidents.  In  the  Emperador's  elevation 
the  soil  is  almost  composed  of  disintegrated  rock,  a  soil  which  can 
be  excavated  by  machine  without  recourse  to  blasting.  In  the 
construction  of  this  section  of  the  canal  were  employed  6  con- 
tinuous digging-machines,  48  drilling-machines,  and  66  cranes 
for  hoisting  the  blasted  rocks. 

The  fourth  section  of  the  canal  includes  the  Culebra  cut,  which 
will  be  the  deepest  trench  ever  excavated  in  the  world.  It  is 
2.1  miles  long  with  depths  suddenly  varying  between  200  and 
377  ft.,  and  it  will  require  the  excavation  of  35,100,000  cu.  yds. 
of  earth.  The  soil  in  this  section,  close  to  the  surface,  was  com- 
posed of  rock,  alternated  with  strata  of  disintegrated  rock,  and 
the  strata  were  very  slippery.  Such  a  fact,  especially  on  beginning 
of  the  work,  caused  enormous  trouble  to  the  engineers.  The  cuts 
made  in  the  day  were  often  filled  up  again  at  night,  and  the  large 
quantity  of  water  flowing  through  the  trenches  during  the  rainy 
season  often  washed  out  the  cuts,  carrying  away  or  undermining 
the  heavy  machines.  Thirty-nine  continuous  excavators  were 
employed  in  this  section  of  the  work,  and  the  excavated  material 
was  hauled  away  by  36  locomotives  and  1300  cars  of  8  cu.  yds. 
capacity,  besides  600  tip-cars  of  the  Decauville  type  of  2  cu.  yds. 
each. 

The  fifth  section  of  the  canal,  8  miles  long,  extends  from  the 
Culebra  hill  to  the  Pacific  Ocean,  following  the  valley  of  the  Rio 
Grande.  The  soil  descends  continuously  toward  the  ocean,  until 
in  the  last  6  miles  it  is  only  10  ft.  above  sea-level.  Both  the 
quality  of  the  soil  and  the  conditions  of  the  work  were  here  similar 
to  those  encountered  in  the  first  section  of  the  canal.  Until  the 
soil  had  a  certain  height  it  was  excavated  by  means  of  the  con- 
tinuous digging-machine,  but  through  the  low  portion  of  this  sec- 


EXAMPLES    OF    LARGE    CANAL    EXCAVATION   WORKS.  353 

tion  the  canal  was  dug  by  dredges.  Eight  continuous  excava- 
tors, served  by  16  locomotive^  360  cars  of  large  capacity,  900 
Decauville  cars  and  7  dredges,  were  employed  in  digging  this  sec- 
tion, which  is  already  entirely  excavated. 

In  connection  with  the  construction  of  the  canal  other  impor- 
tant works  were  required,  one  of  the  principal  being  the  improve- 
ment of  the  Chagres  River.  It  has  been  remarked  that  the  route 
of  the  canal  intersected  several  times  the  Chagres  River,  and  it 
was  then  necessary  to  deviate  its  course.  To  prevent  also  that 
during  the  rainy  season  its  water  will  obstruct  the  navigation,  it 
was  proposed  to  dig  two  parallel  supplementary  canals,  one  on 
each  side  of  the  main,  so  as  to  collect  the  whole  amount  of  water 
flowing  from  the  mountains.  The  total  length  of  these  canals 
would  have  been  27.28  miles,  and  they  were  projected  with  a  cross- 
section  131  ft.  wide  and  a  depth  varying  from  13  to  16  ft.,  involv- 
ing the  excavation  of  millions  of  cubic  -yards  of  earth. 

In  the  excavation  of  the  Panama  Canal  at  times  were  em- 
ployed 13,000  men,  of  which  12,000  were  workmen,  and  1000 
between  foremen,  superintendents,  engineers,  etc.  As  a  rule, 
when  an  excavation  is  effected  in  any  locality,  bacteria  spread  in 
the  air  in  such  quantities  as  to  affect  the  health  not  only  of 
the  laborers,  but  also  that  of  the  inhabitants  living  close  by.  For 
this  reason  are  found  symptoms  of  malaria  near  every  excavation 
of  some  importance,  and  even  in  localities  never  affected  before. 
But  to  excavate  such  an  enormous  amount  of  earth  as  was 
then  required  for  the  construction  of  the  Panama  Canal,  and 
in  a  tropical  region  where  many  other  diseases  are  encountered, 
was  a  hard  proposition.  The  death-rate  among  the  men  em- 
ployed in  this  work  was  something  awful,  being  7J  per  cent, 
among  the  workmen  and  6.4  per  cent,  among  the  employers.  These 
numbers  would  have  certainly  been  doubled  if  it  were  not  for  the 
strict  sanitary  measures  adopted  by  the  company  in  order  to  safe- 
guard the  health  of  its  men,  and  for  the  enormous  expenses  it 
underwent  to  provide  for  the  comfort  of  the  men  greatly  improv- 
ing the  sanitary  conditions  of  the  locality.  European  workmen 
could  not  stand  the  climate  and  were  decimated;  the  only  ones 


354  EARTH  AND  ROCK  EXCAVATION. 

who  could  resist  it  in  those  regions  came  from  Jamaica,  but  they 
were  very  slow  in  their  work, 

From  the  summary  description  of  the  Panama  Canal  as  orig- 
inally projected  by  Mr.  De  Lesseps,  it  is  easily  seen  that  the  great- 
est difficulties  are  encountered  in  Sections  3  and  4  in  the  cutting 
of  the  Obispo,  Emperador,  and  Culebra  trenches.  To  avoid  such 
an  enormous  quantity  of  excavation,  and  greatly  reducing  the 
cost  of  construction  of  the  canal,  it  was  suggested  to  have  a 
sea-level  canal  through  Sections  1,  2,  and  5,  and  a  high-level  canal 
with  9  locks  in  Sections  3  and  4.  With  the  feverish  increasing 
of  dimensions  of  the  ocean  vessels  that  are  now  considered  almost 
small  boats,  those  that  were  considered  large  steamers  at  the 
time  the  Panama  Canal  was  begun,  nobody  could  foresee  the 
future  progress  of  the  interoceanic  navigation,  and  a  high-level 
canal  with  a  series  of  locks  would  be  found  perhaps  of  great  incon- 
venience to  the  enormous  traffic  of  the  Panama  Canal. 


Since  this  chapter  was  written,  the  author  notes  with  pleasure, 
that  -Mr.  John  F.  Wallace,  Chief  Engineer  of  the  Panama  Canal 
Commission,  after  six  months'  residence  on  the  Isthmus,  suggests 
a  sea-level  canal  as  the  most  practical  one,  thus  corroborating  the 
author's  views.  ' 


INDEX. 


Accidents,  336 

Aerialways,  206 

Allen  spring  barrow,  138 

Arrangement  of  tracks,  312,  322 

Austin  trenching-machine,  113 

Automobile  grader,  100 

Earnhardt  steam-shovel  ,119 

Belt  conveyors,  181 

Blasting,  81,  91 

Blasting-machines,  79 

Bleickert  cableway,  224 

Blickford  match,  77 

Boom,  196 

Borrow-pits,  31 

Bourdon  excavator,  110 

Brandt  drilling-machine,  63 

Broderick  cableways,  224 

Brothers  electric  cableway,  249 

Brown    hoisting-    and    conveying-ma- 

chine,  214 

Bruckner's  curve,  36 
Buckets,  263 

Building  embankments,  322 
Buying  the  machines,  284 
Cableways,  220 
Cableways,  Bleickert,  224 

Carrington,  222 

Carson,  230 

Endless  hauling-rope,  228 

Hodgson  &  Hallidie,  223 

Inclined,  239 

Locke-Miller,  233 

Movable,  237 

Calculation  of  cuts  and  fills,  correct 
method,  10 

from  longitudinal  profile,  23 

Mean  end  areas,  13 

Prismoidal  formula,  11 

Profile  of  masses,  21 
Canals,  Chicago,  345 

Manchester,  343 

Panama,  349 

Suez,  340 


Cars,  159 

Number  of,  309,  321' 

Dumping,  163 
Carts,  145 
Chains,  256 

Channeling-machines,  48 
Charge  of  explosives,  85 
Chicago  canal,  345 
Chisel,  53 

Clam-shell  bucket,  130 
Classification  of  materials,  42 
Compensation  of  cuts  and  fills,  25,  31 
Computation  of  earthworks,  compen- 
sating cuts  and  fills,  25 

Profile  and  cross-section,  24 

Reduced  to  grade,  27 
Contour-lines,  3 
Contractors'  benefit,  338 
Construction  work,  319 
Continuous  excavators,  105 
Cost  of  earthworks,  real  cost,  334 

Accidents,  336 

General  expenses,  336 

Interest,  336 
Crane-derrick,  191 
Cranes,  190 
Crowbars,  46,  52 
Curves,  158 
Cuts  and  fills,  30 
Cutting  down  grades,  318 
Davis  Calix,  62 
Derrick,  195 

Stiff-leg,  199 

Guy, 201 

Traveling,  202 
Detonation,  85 
Diamond  drills,  61 
Direction  of  excavations,  287 
Distance  of  drill-holes,  83 
Distribution  of  the  cuts,  33 

Italian  method,  33 

French  method,  34 

355 


356 


INDEX. 


Distribution  of  the  cuts,   Bruckner's 
curve,  36 

Lalanne's  curve,  38 
Down-digging  excavators,  106 
Drag-scrapers,  140 
Drilling,  methods  of,  52 
Drills,  Hand,  53 

Percussion,  54 

Electric,  58 

Rotary,  60 

Dumping-cars,  163,  170 
Dump-carts,  145 
Dumping-wagons,  147 
Dunbar  &  Ruston  Navvy,  122 
Durkee  electric  drill,  58 
Dynamite,  70 
Earthwork,  computation  of,  10,  24 

Cost  of,  9,  334 

Plotting  methods  of,  2 

Shrinkage,  328 
Electric  cableway,  249 

drill,  58 

engine,  268 

excavator,  116 

firing,  78 

telphers,  246 
Elevators,  189 
Embankments,  322 
English  method  of  excavation,  314 
Excavation,  Planning  of,  287 

Hydraulic,  91 
Excavators,  Austin-French,  113 

Continuous,  105 

Intermittent,  118 
Explosion,  85 
Explosives,  Gunpowder,  67 

Nitroglycerine,  69 

Dynamite,  70 

Storage  of,  74 

Transportation,  73 
Firing,  80 

Fixed  track  cableways,  228 
Foot-block,  196 
Force  of  gases  in  gunpowder,  68 

dynamite,  72 

Foreman,  requisites  for,  274 
Fuses,  77 
Grab-hooks,  265 
Graders,  Automobile,  100 

New  Era,  94 
Gravity  roads,  179 
Goodwin  dumping-car,  170 
Gunpowder,  67 
Guy  derrick,  201 
Hauling,  Carts  and  wagons,  145 

Drag-scrapers,  140 

Endless  chain,  177 

Hand-carts,  139 


Hauling,  Inclines  for,  173 

Industrial  railways,  155 

Methods  of,  133 

Traveling  cars,  178 

Wheelbarrows,  136 

Wheeled  scrapers,  142 
Hammer,  53 
Hand-carts,  139 
Hand-drill,  53 
Hand-rollers,  332 

Hodgson  &  Hallidie  cableways,  223 
Hoisting,  186 
Hoisting-engines,  267 
Horse-gin,  188 
Hydraulic  excavation,  91 
Inclined  cableways,  240 
Inclines,  173 
Industrial  railways,  155 
Ingersoll  drill,  55 
Interest,  283,  336 
Intermittent  excavators,  118 
Keystone  Driller  Co.,  66 
Lalanne's  curve,  38 
Land  dredges,  129 
Lidgerwood  transfer,  207 
Lithofacter,  70 
Locke-Miller  cableway,  233 
Locomotives,  166 
Locomotive  crane,  193 
Lowering  the  tracks,  312 
Machine  excavation,  91 
Manchester  canal,  343 
Marked  points,  2 
Marvin  Electric  Drill,  60 
Mast  and  boom,  196 
Materials,  Classification  of,  42 
Mean  distance  of  hauling,  39 
Men,  Number  of,  301 
Moore  trenching-machine,  211 
Motive  power,  270 
Movable  cableways,  237 
Navvy,  122 
New  Era  grader,  94 
Nitroglycerine,  69 
Number  of  cars,  309-322 

men,  301 

trains,  309-321 

wagons,  303 
Open-cut  method,  309 
Orange-peel  bucket,  129    ) 
Otto  cableway,  224 
Panama  canal,  349 
Percussion-drills,  54 
Pick,  90 
Plow,  92 

Plug  and  feather,  48 
Prismoidal  formula,  10 
Profile  and  cross-sections,  3 
Profile  of  masses,  21 


INDEX. 


357 


Profit  of  contractors,  338 

Push-cart,  99 

Kails,  155 

Rapid  unloader,  325 

Removing  the  tracks,  312 

Repairing,  284 

Reversible  engines,  267 

Robins  belt-conveyor,  183 

Rock  excavation,  Hand  methods  of,  44 

Rollers,  332 

Rope,  Manilla,  258 

Wire,  259 
Rotary  drills,  60 
Satre  excavator,  106 
Scales,  262 
Scrapers,  Drag,  140 

Wheeled,  142 

Vivian,  254 
Shoots,  240 
Shovels,  88 

Shrinkage  of  earth,  328 
.Sinking  fund,  284 
Skips,  262 

Sledge-hammers,  46,  90 
.Spade,  89 
Spoil-banks,  31 
•Steam-shovels,  Earnhardt,  119 

Dunbar  &  Ruston,  122 

Operation  of,  118,  317 

Thew  automatic,  125 
Stiff-leg  derrick,  199 
Stone-boat,  153 
Storage  of  explosives,  74 
Sullivan  rotary  drill,  62 
Suez  canal,  340 

Superintendent,  Requisites  for,  274 
Tamping,  79 
Telpherage,  243 
Telphers,  246 
Temperly  transporter,  216 
Thew  automatic  steam-shovel,  125 


Ties,  156 
Tracks,  312 

Arrangement  of,  322 

for  Industrial  railway,  155 
Trains,  309 

Number  of,  321 

Transportation  of  explosives,  73 
Transporters,  Brown,  214 

Lidgerwood,  208 

Moore,  211 

Temperly,  216 
Traveling  derrick,  202 
Trenching-machines,  Austin,  113 

Carson,  230 

Moore,  211 
Turntables,  158 
Unloaders,  325 

Up-digging  excavators,  110,  118 
Vertical  hauling,  186 
Vivian  scraper,  254 
Wagons,  147 

Inclines  for,  174 

Number  of,  303 
Wearing,  284 
Wedges,  46 
Wheelbarrows,  136 

Inclines  for,  173 
Wheeled  scrapers,  142 
Widening  cuts,  317 
Windlass,  186 
Wire  ropes,  197 
Work  of  animals,  280 

machines,  282 

men,  278 

Work  of  excavation,  Industrial  railway, 
307 

New  Era  grader,  292 

Plow  and  scraper,  287 

Wagons,  300 

Wheelbarrows,  297 
Workmen,  Efficiency  of,  275 


Cableway  on  Earth  Canal 


Traveling   Duplex  Cableway — Earth   Excava- 
tion, Illinois  and  flississippi  Canal, 
U.  S.  Government. 

A  digging  machine  operating  two  1%  yard  Orange  Peel 
Buckets  is  here  employed  as  no  other  excavator  would  answer, 
soil  being  too  soft  to  sustain  steam  shovel.  Towers  far  back 
from  canal.  Entire  cost  digging  and  transporting  250  feet  at 
5.9  cents  per  yard.  Record  for  30  days  run  51,074  cubic  yards 
under  extremely  adverse  conditions  in  moving  over  yielding 
and  soft  trackway. 

Lidgerwood  Manufacturing  Company, 

Cableways  and  Logging  Machinery, 

For  Excavating,  Dam  Construction, 
Mines,  Quarries,  Public  Works.     .    . 

96  LIBERTY  ST.,  NEW  YORK. 

LONDON,    BOSTON,    PHILADELPHIA,    ATLANTA. 


Cableway  on  Rock  Canal 


Traveling  Cableway  Loaded  by  Steam  Shovel, 

West  Neblish  Channel— Sault  Ste  Marie 

River.      U.  S.  Government. 

Four  10  ton  Traveling  Cable  ways  on  rock  cut  300  feet  wide 
in  bed  of  river,  water  cut  off  with  coffer  dams.  Skips  loaded 
with  65  ton  Steam  Shovels.  Demonstrated  capacity  700  cubic 
yards  place  measure  10  hours.  Cableways  can  handle  more 
than  shovels  can  load.  27,500  cubic  yards  place  measure  in  30 
days  actually  handled. 


Lidgerwood  Manufacturing  Company, 

Hoisting  Engines  and  Electric  Hoists, 

Standard  for  Quality  and  Duty, 
Interchangeable  Part  System. 

96   LIBERTY  ST.,  NEW  YORK. 

CHICAGO,    CLEVELAND,    NEW   ORLEANS,    SEATTLE. 


The  Chicago  Sewer  Excavator, 


Sewers, 

Water= 

Works, 

Gas  and 

Conduit 

Lines. 

Does  the 
work  of 
150  Men. 


No.  3  Machine  digging  ditch  20  feet  deep,  60  inches  wide. 


THESE  MACHINES  will  dig  any  depth  up  to  22  feet. 
Width  of  from  14  inches  to  60  inches. 
We  build  various  sizes. 

Machines  Leased  to   Contractors. 


Write  us  particulars  and  ask  about  control  ot  territory. 


Municipal  Engineering  &  Contracting  Co. 

607-611  Railway  Exchange  Building, 

CHICAGO,  ILLINOIS,  U.  S.  A. 


Robins  Belt  Conveyor  Handling  Excavated  Earth  and  Rock. 

*ITN  excavating,  it  is  the  contractor's  purpose  to 
remove  the  earth  and  rock  in  the  shortest 
possible  time  and  at  least  cost. 
For  this  purpose  the 

IRobfns  Belt  Convenor 


combines  great  capacity  and  durability  with  econ- 
omy and  portability. 


"\7\7"rito   for 


ROBINS  CONVEYING  BELT  CO. 

PARK  ROW  BUILDING,  NEW  YORK, 


ROCK 


EXCAVATING 
MACHINERY. 


ROCK   DRILLS. 

Standard  of  the  world.     Over  76,000  built  and  sold. 


The  "Sergeant." 

An  independent  valve  type,  ac- 
cepted as  the  best  all-around  drill  for 
hardest  rock. 

The  "  Little  Giant." 

A  tappet  valve  type  of  recognized 
superiority,  especially  adapted  to  the 
use  of  steam. 


Hammer  Drills. 
The  Tittle  Jap,"  The  "Little  Imp," 

The  standard  power  drills  for 
hand  work.  For  mine,  tunnel, 
quarry  and  contract.  Light, 
powerful,  simple  and  economical. 


INGERSOLL-RAND  CO 

II  Broadway,  New  York. 


ROCK 


EXCAVATING 
MACHINERY. 


Stone  Channelers. 

The  standard  for  heavy  rock  work. 
Steam  and  air  driven  for  all  rocks. 
The  most  powerful  and  economical 
channeling  machines  made. 

Davis  Calyx  Core  Drill. 

The  "  diamondless  "  core  drill,  for 
prospecting  to  all  depths  in  rock  of 
every  quality. 


Air  Compressors. 

The  standard  for  all  classes 
of  service. 

Fifteen  distinct  types. 

More  than  a  thousand  sizes. 

Economical,  Simple,  Reli- 
able. 


INGERSOLL-RAND  CO 

II  Broadway,  New  York. 


The  Problem  of 


handling  Earth  Rock 
and  other  materials 
has  been  solved  by  the 
Hayward  Digging 
Buckets  and  Digging 
Machines. 

If  you  are  interested  in 
Orange  Peel  Buckets, 
Clam  Shell  Buckets,  Bot- 
tom Dump  Buckets,  Turn- 
over Buckets  as  well  as 
Dredges,  Skid  Excava- 
tors, Derricks,  Derrick  Fixtures,  Steel  Traveling  Der- 
ricks or  Coal  Handling  Machinery, 

Send  for  our  catalogue  in  which  they  are  fully 
illustrated  and  described. 


THE   HAYWARD  COMPANY, 

97-103   CEDAR  STREET, 
NEW  YORK,  N.  Y. 


There  are  Just  Two  Kinds  of  Wire  Rope 

"POWERSTEEL"  ROPE,  and  others. 


"POWERSTEEL"  Rope  received  the  highest  award  at  two 
expositions,  and  is  especially  adapted  for  heavy  work.  Isj  made 
with  one  yellow  Strand. 


OUR  AERIAL  WIRE   ROPE  TRAMWAYS 

HAVE    THE 

G.  <fe  S.  Patent  Self-locking,  Self-righting  and  self-diimping  bucket. 
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BRODERICK  &  BASCOM  ROPE  CO, 

ST.  LOUIS,  HO. 


NEW  YORK  OFFICE,  19  MURRAY  STREET. 


G.  L  Stuebner,  Iron  Works 

FOOT  OF  llth  and  12th  STREETS, 

LONG  ISLAND  CITY,  N.  Y. 


MANUFACTURERS 


Self=Dumping  and 

Self=Righting 
Hoisting  Buckets 
for  Contractors 
use,  Stuebner's 
Patent  "EXCELSIOR"  Bottom  dumping 
Bucket  for  handling  Concrete  and  other 
Materials. 

Narrow  Gauge  V  shaped  Tip  Cars. 
Portable  Track  and  Switches. 
Wheelbarrows,  Hoisting  Blocks,  Etc. 

Send  for    Catalogue 


Not  by  idle  claims  of  superiority — not  by  a  comparison 
of  price,  but  by  actual  test  in  the  real  world  of  work,  has  the 

Watson  Dumping  Wagon 

achieved  its   present   advanced   position.      Looked  upon  as 
"  freakish,"  twenty  years  ago,  it  is  the  accepted  and  standard 

type   to-day. 

Has  many  imita- 
tors but  not  a  real 
rival  in  the  world  of 
contracting. 


The  first  Bottom  Dumping  Wagon  in  the  field.  The  last  wagon  on 
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Spokes  of  selected,  tested,  second-growth,  white  oak.  Unmatchable  and 
unbreakable. 

Watson  Dumping  Wagons  are  first  in  every  big  earth 
moving  proposition. 


WATSON  WAGON  CO. 

Main  Office  and  Factory,  Canastota,  N.  Y. 


The  Largest  Dumping  Wagon  Plant  in  the  World. 


IS  CT  V  Q  T  fMVI  ET  BLAST-HOLE  DRILLERS 

IX  Cl    I    O     I     X-/IMCL      AND  WELL    MACHINERY 

For  CONTRACTORS. 

THE   KEYSTONE  SPUDDING  DEVICE 

allows  the  tools  to  be  raised  or  lowered  or  entirely  withdrawn,  without  stop- 
ping the  engine  and  in  a  moment's  time.  No  pulling  down  of  slack  or  climb- 
ing up  on  machine  to  remove  rope  from  sheave  while  the  tools  rest  on  the 
bottom  of  the  hole  with  every  chance  of  being  buried  by  a  cave-in.  On  the 
KEYSTONE  two  motions  of  a  lever  at  the  drillers  hand  start  the  tools  for  the 
surface. 

THE  KEYSTONE  CROSS  TUBULAR  (PORCUPINE)  BOILER 

entirely  does  away  with  the  hot  and  dirty  task  of  daily  or  tri-daily  flue  swab- 
bing. Tubes  rarely  need  attention  and  when  they  do,  a  laborer  with  a  wrench 
And  a  nipple  of  gas  pipe  can  do  the  work.  Free  draught  allows  continuous 
combustion  ;  will  burn  anything  from  green  wood  to  hard  coal. 

THE  KEYSTONE  TRACTION  MACHINE 

will  go  anywhere  in  reason  under  its  own  steam.  No  waiting  for  horses  or 
delay  hitching  and  unhitching. 

THE  KEYSTONE  GAIT 

means  a  speed  that  can't  be  attempted  by  any  other  machine  in  the  field. 
Our  tools  and  minor  parts  are  made  to  stand  up  under  the  usage.  Some  of 
our  machines  have  been  in  use  for  16  and  18  years.  They  are  built  for  service. 

Send  for  Catalogue,  No.  4  of  Contractor's  Drills. 

Catalogues,  No.  1,  No.  2,  and  No.  3,  describe   Water,  Mineral  Test  and 
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Keystone  Driller  Co.,  =  Beaver  Falls,  Pa. 


Balbwin  Xocomotive  Moths. 


Broad 

and  Narrow 
Gauge 


MINE, 
FURNACE 
AND  IN- 
DUSTRIAL 
LOCOMO- 
TIVES. 


LOCOMOTIVES 


Single 
Expansion 
and  Compound 


ELECTRIC 
LOCOMO- 
TIVES WITH 
WESTING  - 
HOUSE 
MOTORS 
AND 

ELECTRIC 
TRUCKS. 


Locomotives  particularly  adapted  to  Contractors'  Service, 

Burnham  Williams  &  Co., 


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IBOOIKIS   IFOIR, 

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PERLINI  C.  Tunneling.  A  practical  Treatise  containing  149  Working 
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''Engineering  News."  Third  Edition  JRemsed.  311  pages.  8vo,  cloth,  illus- 
trated  $3.00 

WARREN,  F.  D.  Handbook  on  Reinforced  Concrete,  for  Architects,  En- 
gineers and  Contractor*.  With  figures,  diagrams  and  numerous  tables.  12mo. 
Cloth.  Illustrated net  $2.50 

ZIMMER,  G.  F.  Mechanical  Handling  of  Material.  Being  a 
treatise  on  the  handling  of  material,  such  as  coal,  ore,  timber,  etc.,  by  automatic 
and  semi-automatic  machinery.  With  542  figures,  diagrams  full-page  and 
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ABBOT,   H.   L.,   Gen'l,     The  Defence   of  the  Seacoast  of 

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ADAMS,  J.  W.  Sewers  and  Drains  for  Populous  Dis- 
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ADDYMAN,    F.    T.      Practical    X-Ray    Work.      Part    I, 

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ALEXANDER,  S.  A.     Broke  Down:    What  Should  I  Do? 

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ANDERSON,  G.  L.,  A.M.     (Captain    of   U.  S.  Artillery). 

Handbook  for  the  use  of  Electricians  in  the  operation  and  care 
of  Electrical  Machinery  and  Apparatus  of  the  United  States  Sea- 
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General  Commanding  the  Army.  With  tables,  diagrams  and 
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ANDERSON,  J.    W.     Prospector's   Handbook.     A   Guide 

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Valuable  Minerals.  Eighth  Edition,  revised.  8vo,  cloth.  .  .  .  $1 .50 

ANDERSON,  W.     On  the  Conversion  of  Heat  into  Work. 

A  Practical  Handbook  on  Heat-engines.  Third  Edition.  Illus- 
trated. 12mo,  cloth $2 . 25 

ANDES,  L.     Vegetable    Fats    and    Oils:     Their    Practical 

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Their  Properties,  Adulteration  and  Examination.  A  Handbook 
for  Oil  Manufacturers  and  Refiners,  Candle,  Soap  and  Lubricating- 
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lated from  the  German.  With  94  illus.  8vo,  cloth net,  $4 . 00 

Animal  Fats  and  Oils.  Their  Practical  Produc- 
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Agriculturists,  Tanners,  etc.  Translated  by  Charles  Salter. 
With  62  illustrations.  8vo,  cloth net,  $4 . 00 

Drying  Oils,  Boiled  Oil,  and  Solid  and  Liquid  Driers. 

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Iron     Corrosion,     Anti-fouling     and     Anti-corrosive 

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Oil  Colors,  and  Printers'  Ink.  A  Practical  Hand- 
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56  figures  and  diagrams.  8vo,  cloth,  212  pages net,  $2.50 

ANNUAL  REPORTS  on  the  Progress  of  Chemistry  for  1904. 
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Vol.  II  (1905).  8vo,  cloth net,  $2.00 


SCIENTIFIC  PUBLICATIONS.  3 

ARNOLD,    E.       Armature    Windings    of     Direct-Current 

Dynamos.  Extension  and  Application  of  a  General  Winding 
Rule.  Translated  from  the  original  German  by  Francis  B, 
DeGress,  M.E.  With  numerous  illustrations.  8vo,  cloth. .  .  $2 . 00 

ARNOLD,  R.,  Dr.  Ammonia  and  Ammonium  Com- 
pounds. A  Practical  Manual  for  Manufacturers,  Chemists,  Gas 
Engineers  and  Drysalters.  Second  Edition.  12mo,  cloth... .  $2 . 00 

Art  of  Dyeing  Wool,  Silk  and  Cotton.     Translated  from 

the  French  of  M.  Hellott,  M.  Macquer  and  M.  Le  Pileur  D'Apligny. 
First  published  in  English  in  1789.  8vo,  cloth,  illustrated,  net,  $2 . 00 

ASHE,   S.  W.,   and  KEILEY,   J.  D.     Electric  Railways, 

Theoretically  and  Practically  Treated;  Rolling  Stock.  With 
numerous  figures,  diagrams,  and  folding  plates.  12mo,  cloth, 

illustrated net ,  $2 . 50 

Vol.  2.     Sub-stations  and  the  Distributing  System In  Press. 

ATKINSON,   A.   A.,   Prof.     (Ohio   University).     Electrical 

and  Magnetic  Calculations,  for  the  use  of  Electrical  Engineers  and 
Artisans,  Teachers,  Students  and  all  others  interested  in  the 
Theory  and  Application  of  Electricity  and  Magnetism.  Second 
Edition,  revised.  8vo,  cloth,  illustrated net,  $1 . 50 

ATKINSON,    P.      The     Elements     of    Electric     Lighting, 

including  Electric  Generation,  Measurement,  Storage  and  Dis- 
tribution. Tenth  Edition,  fully  revised  and  new  matter  added. 
Illustrated.  12mo,  cloth $1 . 50' 

-  The  Elements  of  Dynamic  Electricity  and  Mag- 
netism. Fourth  Edition.  120  illustrations.  12mo,  cloth.  .  $2.00 

Power  Transmitted  by  Electricity  and  its  Appli- 
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struction. Fourth  Edition,  fully  revised,  new  matter  added. 
12mo,  cloth,  illustrated $2 . 00 

AUCHINCLOSS,  W.  S.  Link  and  Valve  Motions  Sim- 
plified. Illustrated  with  29  woodcuts  and  20  lithographic  plates , 
together  with  a  Travel  Scale,  and  numerous  useful  tables.  Four- 
teenth Edition,  revised.  8vo,  cloth $2 . 00 

AYRTON,   H.     The   Electrical  Arc.     With  numerous  fig-- 

ures,  diagrams  and  plates.     8vo,  cloth,  illustrated $5.00 

AYRTON,  W.  E.,  M.I.C.E.  Practical  Electricity.  A  Labo- 
ratory and  Lecture  Course  for  the  first-year  students  of  Electrical 
Engineering,  based  on  the  International  Definitions  of  the  Electri- 
cal Units.  Vol.  I,  Current,  Pressure,  Resistance,  Energy,  Power, 
and  Cells.  Completely  rewritten  and  containing  many  figures 
and  diagrams.  12mo,  cloth $2 . 00 


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BACON,  F.  W.     A  Treatise  on  the  Richards  Steam-engine 

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Revised,  with  notes  and  large  additions  as  developed  by  American 
practice;  with  an  appendix  containing  useful  formulse  and  rules 
for  engineers.  Illustrated.  Fourth  Edition.  12mo,  cloth.  .  $1 .00 

BAKER,  Arthur  L.,  Prof.  (Univ.  of  Rochester).  Quater- 
nions   In  Press. 

BAKER,  M.  N.  Potable  Water  and  Methods  of  Detect- 
ing Impurities.  New  Edition,  revised  and  largely  rewritten.  16mo, 
cloth.  ( Van  Nostrand's  Science  Series) $0 . 50 

BALCH,    G.    T.,    Col.     Methods    of    Teaching    Patriotism 

in  the  Public  Schools.     8vo,  cloth $1 . 00 

BALE,   M.   P.     Pumps   and   Pumping.     A   Handbook   for 

Pump  Users.     12mo,  cloth $1 . 50 

BALL,  S.  R.     Popular  Guide  to  the  Heavens.     A  series  of 

eighty-three  plates,  many  of  which  are  colored  and  lithographed, 
with  explanatory  text  and  index.  Small  4to,  cloth,  illustrated. 

net,  $4.50 

BARBA,  J.     The  Use  of  Steel  for  Constructive  Purposes. 

Method  of  Working,  Applying  and  Testing  Plates  and  Bars. 
With  a  Preface  by  A.  L.  Holley,  C.E.  12mo,  cloth $1 .50 


BARKER,   A.    H.     Graphic   Methods   of   Engine    Design 

Including  a  Graphical  Treatment  of  the  Balancing  of  Engines. 
12mo,  cloth $1 . 50 

BARNARD,  F.  A.  P.  Report  on  Machinery  and  Pro- 
cesses of  the  Industrial  Arts  and  Apparatus  of  the  Exact  Sciences 
at  the  Paris  Universal  Exposition,  1867.  152  illustrations  and 
8  folding  plates.  8vo,  cloth $5 . 00 

BARNARD,  J.  H.     The  Naval  Militiaman's  Guide.     Full 

leather,  pocket  size $1 . 25 

BARRUS,   G.   H.     Boiler  Tests:    Embracing  the   Results 

of  one  hundred  and  thirty-seven  evaporative  tests,  made  on 
seventy-one  boilers,  conducted  by  the  author.  8vo,  cloth .  $3 . 00 

Engine  Tests:     Embracing  the   Results  of   over  one 

hundred  feed-water  tests  and  other  investigations  of  various 
kinds  of  steam-engines,  conducted  by  the  author,  With  numer- 
ous figures,  tables,  and  diagrams.  8vo,  cloth,  illustrated.  .  $4.00 
The  above  two  purchased  together $6.00 


SCIENTIFIC  PUBLICATIONS.  5 

BARWISE,    S.,    M.D.    (London).      The    Purification    of 

Sewage.  Being  a  brief  account  of  the  Scientific  Principles  of 
Sewage  Purification  and  their  Practical  Application.  12mo, 
cloth,  illustrated.  New  Edition net ,  $3 . 50 

BEAUMONT,    R.     Color    in    Woven    Design.    With    32 

colored  plates  and  numerous  original  illustrations.  Large, 
12mo $7.50 

W.  W.  Practical  Treatise  on  the  Steam-engine  In- 
dicator, and  Indicator  Diagrams.  With  notes  on  Engine  Per- 
formances, Expansion  of  Steam,  Behavior  of  Steam  in  Steam- 
engine  Cylinders,  and  on  Gas-  and  Oil-engine  Diagrams.  Second 
Edition,  revised  and  enlarged.  8vo,  cloth,  illustrated. .  .net,  $2.50 

BEECH,    F.     Dyeing    of    Cotton    Fabrics.    A    Practical 

Handbook  for  the  Dyer  and  Student.  Containing  numerous 
recipes  for  the  production  of  Cotton  Fabrics  of  all  kinds,  of  a  great 
range  of  colors,  thus  making  it  of  great  service  in  the  dye-house, 
while  to  the  student  it  is  of  value  in  that  the  scientific  principles 
which  underlie  the  operations  of  dyeing  are  clearly  laid  down. 
With  44  illustrations  of  Bleaching  and  Dyeing  Machinery.  8vo, 
cloth,  illustrated net,  $3 .00 

Dyeing    of    Woolen    Fabrics.     With    diagrams    and 

figures.     8vo,  cloth,  illustrated net,  $3 . 50 

BECKWITH,  A.     Pottery.     Observations  on  the  Materials 

and  Manufacture  of  Terra-cotta,  Stoneware,  Firebrick,  Porce- 
lain, Earthenware,  Brick,  Majolica,  and  Encaustic  Tiles.  Second 
Edition.  8vo,  paper 60 

BEGTRUP,  J.,  M.E.      The  Slide  Valve  and  its  Functions. 

With  Special  Reference  to  Modern  Practice  in  the  United  States. 
With  numerous  diagrams  and  figures.  8vo,  cloth $2.00 

BERNTHASEN,  A.      A  Text-book  of  Organic  Chemistry. 

Translated  by  George  M'Gowan,  Ph.D.  Fifth  English  Edition, 
revised  and  extended  by  author  and  translator.  Illustrated. 
12mo,  cloth In  Press. 

BERRY,  W.  J.  Differential  Equations  of  the  First  Species. 
12mo,  cloth,  illustrated In  Press. 


6  D.  VAN  NOSTRAND  COMPANY'S 

BERSCH,    J.,    Dr.      Manufacture    of    Mineral    and    Lake 

Pigments.  Containing  directions  for  the  manufacture  of  all 
artificial  artists'  and  painters'  colors,  enamel  colors,  soot  and 
metallic  pigments.  A  text-book  for  Manufacturers,"  Merchants, 
Artists  and  Painters.  Translated  from  the  second  revised  edition 
by  Arthur  C.  Wright,  M.A.  8vo,  cloth,  illustrated net,  $5.00 

BERTIN,  L.  E.      Marine  Boilers:   Their  Construction  and 

Working,  dealing  more  especially  with  Tubulous  Boilers.  Trans- 
lated by  Leslie  S.  Robertson,  Assoc.  M.  Inst.  C.  E.,  M.  I.  Mech.  E., 
M.I.N.A.,  containing  upward  of  250  illustrations.  Preface  by 
Sir  William  White,  K.C.B.,  F.R.S.,  Director  of  Naval  Construc- 
tion to  the  Admiralty,  and  Assistant  Controller  of  the  Navy. 
Second  Edition,  revised  and  enlarged.  8vo,  cloth,  illustrated. 

net,  $5.00 

BIGGS,   C.   H.   W.       First  Principles   of  Electricity   and 

Magnetism.  A  book  for  beginners  in  practical  work,  containing 
a  good  deal  of  useful  information  not  usually  to  be  found  in 
similar  books.  With  numerous  tables  and  343  diagrams  and 
figures.  12mo,  cloth,  illustrated $2 . 00 

BINNS,  C.  F.      Ceramic  Technology.     Being  Some  Aspects 

of  Technical  Science  as  applied  to  Pottery  Manufacture.  8vo, 
cloth net,  $5.00 

-  Manual  of  Practical  Potting.      Compiled  by  Experts. 

Third  Edition,  revised  and  enlarged.     8vo,  cloth net,  $7 . 50 

BIRCHMORE,  W.  H.,  Dr.      How  to  Use  a  Gas  Analysis. 

12mo,  cloth,  illustrated net,  $1 . 25 

BLAKE,  W.  H.     Brewer's  Vade  Mecum.     With  Tables  and 

marginal  reference  notes.     8vo,  cloth net,  $4 . 00 

-  W.  P.     Report    upon    the    Precious    Metals.     Being 

Statistical  Notices  of  the  Principal  Gold  and  Silver  producing 
regions  of  the  world,  represented  at  the  Paris  Universal  Exposi- 
tion. 8vo,  cloth $2 . 00 

BLAKESLEY,  T.  H.     Alternating  Currents  of  Electricity. 

For  the  use  of  Students  and  Engineers.  Third  Edition,  enlarged. 
12mo,  cloth $1 .50 

BLYTH,   A.   W.,   M.R.C.S.,    F.C.S.     Foods:    Their   Com- 

position  and  Analysis.  A  Manual  for  the  use  of  Analytical 
Chemists,  with  an  Introductory  Essay  on  the  History  of  Adultera- 
tions. With  numerous  tables  and  illustrations.  Fifth  Edition, 
thoroughly  revised,  enlarged  and  rewritten.  8vo,  cloth $7.50 


SCIENTIFIC  PUBLICATIONS.  7 

BLYTH,  A.  W.,  M.R.C.S.,  F.C.S.,  Poisons:  Their  Effects  and 

Detection.  A  Manual  for  the  use  of  Analytical  Chemists  and 
Experts,  with  an  Introductory  Essay  on  the  Growth  of  Modern 
Toxicology.  New  Edition In  Press. 

BODMER,   G.  R.     Hydraulic  Motors  and  Turbines.     For 

the  use  of  Engineers,  Manufacturers  and  Students.  Third  Edi- 
tion, revised  and  enlarged.  With  192  illustrations.  12mo, 
cloth $5.00 

BOILEAU,  J.  T.     A  New  and  Complete  Set  of  Traverse 

Tables,  showing  the  Difference  of  Latitude  and  Departure  of 
every  minute  of  the  Quadrant  and  to  five  places  of  decimals. 
8vo,  cloth $5 . 00 

BONNEY,     G,    E.      The     Electro-platers'   Handbook.      A 

Manual  for  Amateurs  and  Young  Students  of  Electro-metallurgy. 
60  illustrations.  12mo,  cloth $1 . 20 

BOOTH,  W.  H.  Water  Softening  and  Treatment,  Con- 
densing Plant,  Feed  Pumps,  and  Heaters  for  Steam  Users  and 
Manufacturers.  8vo,  cloth,  illustrated net,  $2.50 

BOURRY,  E.     Treatise  on  Ceramic  Industries.    A  Complete 

Manual  for  Pottery,  Tile  and  Brick  Works.  Translated  from 
the  French  by  Wilton  P.  Rix.  With  323  figures  and  illustrations. 
8vo,  cloth,  illustrated net,  $8 . 50 

BOW,  R.  H.  A  Treatise  on  Bracing.  With  its  applica- 
tion to  Bridges  and  other  Structures  of  Wood  or  Iron.  156  illus- 
trations. 8vo,  cloth $1 . 50 

BOWIE,   AUG.   J.,   Jr.,   M.E.      A    Practical    Treatise   on 

Hydraulic  Mining  in  California.  With  Description  of  the  Use 
and  Construction  of  Ditches,  Flumes,  Wrought-iron  Pipes  and 
Dams;  Flow  of  Water  on  Heavy  Grades,  and  its  Applicability, 
under  High  Pressure,  to  Mining.  Ninth  Edition.  Small  quarto, 
cloth.  Illustrated $5 . 00 

BOWKER,  Wm.   R.      Dynamo,   Motor    and   Switchboard 

Circuits.  For  Electrical  Engineers.  A  practical  book,  dealing 
with  the  subject  of  Direct,  Alternating,  and  Polyphase  Currents. 
With  over  100  diagrams  and  engravings.  8vo,  cloth.  .  net,  $2.25 

BOWSER,    E.    A.,    Prof.     An    Elementary    Treatise    on 

Analytic  Geometry.  Embracing  Plane  Geometry,  and  an  Intro- 
duction to  Geometry  of  three  Dimensions.  Twenty-first  Edition. 
12mo,  cloth net,  $1 . 75 


8  D.  VAN  NOSTRAND  COMPANY'S 

BOWSER,  E.  A.,   Prof.     An   Elementary  Treatise   on  the 

Differential  and  Integral  Calculus.  With  numerous  examples. 
Twenty-first  Edition.  Enlarged  by  640  additional  examples. 
12mo,  cloth net,  $2 . 25 

—  An  Elementary  Treatise  on  Analytic  Mechanics.  With 

numerous  examples.     Sixteenth  Edition.     12mo,  cloth,  .net,  $3.00 

-An  Elementary  Treatise  on  Hydro-mechanics.     With 

numerous  examples.     Fifth  Edition.     12mo,  cloth net,  $2 .  cO 

-A  Treatise  on  Roofs  and  Bridges.     With  Numerous 

Exercises,  especially  adapted  for  school  use.  12mo,  cloth. 
Illustrated net,  $2 . 25 

BRASSEY'S   Naval   Annual   for    1905.     Edited   by   T.   A. 

Brassey.  With  numerous  full-page  diagrams,  half-tone  illustra- 
tions and  tables.  Nineteenth  year  of  publication.  8vo,  cloth, 
illustrated net,  $6.00 

BRAUN,  E.     The  Baker's  Book:    A  Practical  Handbook 

of  the  Baking  Industry  in  all  Countries.  Profusely  illustrated 
with  diagrams,  engravings,  and  full-page  colored  plates.  Trans- 
lated into  English  and  edited  by  Emil  Braun.  Vol.  I.,  8vo, 

cloth,  illustrated,  308  pages . . . . $2 . 50 

Vol.  II.  363  pages,  illustrated $2. 50 

British    Standard    Sections.     Issued    by    the    Engineering 

Standards  Committee,  Supported  by  The  Institution  of  Civil 
Engineers,  The  Institution  of  Mechanical  Engineers,  The  Institu- 
tion of  Naval  Architects,  The  Iron  and  Steel  Institute,  and  The 
Institution  of  Electrical  Engineers.  Comprising  9  plates  of 
diagrams,  with  letter-press  and  tables.  Oblong  pamphlet, 
8fXl5 $1.00 

BROWN,  WM.  N.     The  Art  of  Enamelling  on  Metal.  With 

figures  and  illustrations.     12mo,  cloth,  illustrated net,  $1 .00 

-  Handbook  on  Japanning  and  Enamelling,  for  Cycles, 
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History  of  D3corative  Art.     With  Designs  and  Illus- 
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SCIENTIFIC  PUBLICATIONS.  9 

BROWN,    WM.  N.     Principle    and    Practice    of    Dipping, 

Burnishing,  Lacquering  and  Bronzing  Brass  Ware.     12mo,  cloth. 

net,  $1.00 

Workshop  Wrinkles  for  Decorators,  Painters,  Paper- 
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BUCHANAN,  E.  E.     Tables  of  Squares.     Containing  the 

square  of  every  foot,  inch,  and  sixteenth  of  an  inch,  between  one 
sixteenth  of  an  inch  and  fifty  feet.  For  Engineers  and  Calcu- 
lators. 16mo,  oblong,  cloth $1 . 00 

BULMAN,   H.   F.,  and   REDMAYNE,   R.  S.   A.     Colliery 

Working  and  Management;  comprising  the  duties  of  a  colliery 
manager,  the  superintendence  and  arrangement  of  labor  and 
wages,  and  the  different  systems  of  working  coal-seams.  With 
engravings,  diagrams,  and  tables.  Second  Edition,  revised  and 
enlarged.  8vo,  cloth,  illustrated net,  $6 . 00 

BURGH,  N.  P.     Modern  Marine  Engineering,  Applied  to 

Paddle  and  Screw  Propulsion.  Consisting  of  36  colored  plates, 
259  practical  woodcut  illustrations  and  403  pages  of  descriptive 
matter.  The  whole  being  an  exposition  of  the  present  practice 
of  James  Watt  &  Co.,  J.  &  G.  Rennie,  R.  Napier  &  Sons,  and 
other  celebrated  firms.  Thick  quarto,  half  morocco $10 . 00 

BURT,  W.  A.     Key  to  the  Solar  Compass,  and  Surveyor's 

Companion.  Comprising  all  the  rules  necessary  for  use  in  the 
field;  also  description  of  the  Linear  Surveys  and  Public  Land 
System  of  the  United  States,  Notes  on  the  Barometer,  Sugges- 
tions for  an  Outfit  for  a  Survey  of  Four  Months,  etc.  Seventh 
Edition.  Pocket  size,  full  leather $2 . 50 

BUSKETT,    E.    W.     Fire    Assaying.     i2mo,    cloth,    illus- 
trated  In  Press. 

CAIN,   W.,   Prof.     Brief   Course   in   the    Calculus.     With 

figures  and  diagrams.     8vo,  cloth,  illustrated net,  $1.75 

Theory    of    Steel-concrete    Arches    and    of    Vaulted 

Structures.  New  Edition,  revised  and  enlarged.  16mo,  cloth,  il- 
lustrated. (Van  Nostrand  Science  Series). . ; $0 . 50 

CAMPIN,    F.     On    the    Construction    of    Iron    Roofs.     A 

Theoretical  and  Practical  Treatise,  with  woodcuts  and  plates  of 
roofs  recently  executed.  8vo,  cloth $2 . 00 


10  D.  VAN  NOSTRAND  COMPANY'S 

CARPENTER,  Prof.  R.  C.,  and  DIEDERICHS,  Prof.  H. 

Internal  Combustion  Motors.  With  figures  and  diagrams.  8vo. 
cloth,  illustrated In  Press, 

CARTER,  E.  T.  Motive  Power  and  Gearing  for  Elec- 
trical Machinery.  A  treatise  on  the  Theory  and  Practice  of  the 
Mechanical  Equipment  of  Power  Stations  for  Electrical  Supply 
and  for  Electric  Traction.  Second  Edition,  revised  in  part  by  G. 
Thomas-Da  vies.  8vo,  cloth,  illustrated $5.00 

CATHCART,   WM.   L.,   Prof.     Machine   Design.     Part   I. 

Fastenings.    8vo,  cloth,  illustrated net,  $3 . 00 

Machine  Elements ;    Shrinkage  and  Pressure  Joints. 

With  tables  and  diagrams In  Press. 

Marine-Engine  Design In  Press. 

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to  Mechanical  Engineering In  Press 

CHAMBER'S   MATHEMATICAL    TABLES,    consisting   of 

Logarithms  of  Numbers  1  to  108,000,  Trigonometrical,  Nautical 
and  other  Tables.  New  Edition.  8vo,  cloth $1 . 75 

CHARPENTIER,    P.     Timber.    A    Comprehensive    Study 

of  Wood  in  all  its  Aspects,  Commercial  and  Botanical.  Show- 
ing the  Different  Applications  and  Uses  of  Timber  in  Various 
Trades,  etc.  Translated  into  English.  8vo,  cloth,  ill  us. .  .  net,  $6 . 00 

CHAUVENET,    W.,    Prof.     New    Method    of    Correcting 

Lunar  Distances,  and  Improved  Method  of  Finding  the  Error 
and  Rate  of  a  Chronometer,  by  Equal  Altitudes.  8 vo,  cloth.  $2.00 

CHILD,    C.    T.     The    How   and   Why   of   Electricity.     A 

Book  of  Information  for  non-technical  readers,  treating  of  the 
Properties  of  Electricity,  and  how  it  is  generated,  handled,  con- 
trolled, measured  and  set  to  work.  Also  explaining  the  opera- 
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CHRISTIE,  W.  W.  Boiler-waters,  Scale,  Corrosion,  Foam- 
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Chimney  Design  and  Theory.     A  Book  for  Engineers 

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SCIENTIFIC  PUBLICATIONS.  11 

CHRISTIE,  W.  W.  Furnace  Draft:  its  Production  by  Me- 
chanical Methods.  A  Handy  Reference  Book,  with  figures  and 
tables.  16mo,  cloth,  illustrated.  (Van Nostrand's  Science  Series). 

$0.50 

CLAPPERTON,   G.     Practical   Paper-making.    A   Manual 

for  Paper-makers  and  Owners  and  Managers  of  Paper  Mills,  to 
which  is  appended  useful  tables,  calculations,  data,  etc.,  with 
illustrations  reproduced  from  micro-photographs.  12mo,  cloth, 
illustrated $2.50 

CLARK,  D.   K.,   C.E.     A  Manual  of  Rules,  Tables  and 

Data  for  Mechanical  Engineers.  Based  on  the  most  recent  inves- 
tigations. Illustrated  with  numerous  diagrams.  1012  pages.  8vo, 
cloth.  Sixth  Edition $5 . 00 

Fuel :    its  Combustion  and  Economy ;  consisting  of 

abridgments  of  Treatise  on  the  Combustion  of  Coal.  By  C.  W. 
Williams,  and  the  Economy  of  Fuel,  by  T.  S.  Prideaux.  With 
extensive  additions  in  recent  practice  in  the  Combustion  and 
Economy  of  Fuel,  Coal.  Coke,  Wood,  Peat,  Petroleum,  etc. 
Fourth  Edition.  12mo,'  cloth $1 . 50 

The   Mechanical   Engineer's   Pocket-book  of    Tables, 

Formulae,  Rules  and  Data.  A  Handy  Book  of  Reference  for 
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Edition,  carefully  revised  throughout $3 . 00 

Tramways :  Their  Construction  and  Working.  Em- 
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the  various  modes  of  traction,  a  description  of  the  varieties  of 
rolling  stock,  and  ample  details  of  Cost  and  Working  Expenses. 
Second  Edition,  rewritten  and  greatly  enlarged,  with  upwards  of  400 
illustrations.  Thick  8vo,  cloth $89.00 

CLARK,  J.  M.  New  System  of  Laying  Out  Railway  Turn- 
outs instantly,  by  inspection  from  tables.  12mo,  cloth.  .  .  $1.00 

CLAUSEN-THUE,  W.     The  ABC  Universal  Commercial 

Electric  Telegraphic  Code;  specially  adapted  for  the  use  of 
Financiers,  Merchants,  Ship-owners,  Brokers,  Agents,  etc.  Fourth 

Edition.     8vo,  cloth $5 . 00 

Fifth  Edition  of  same $7 . 00 

The  A  1   Universal  Commercial  Electric  Telegraphic 

Code.  Over  1240  pages  and  nearly  90,000  variations.  8vo, 
cloth.  .  $7.50 


12  D.  VAN  NOSTRAND  COMPANY'S 

CLEEMANN,   T.   M.     The   Railroad   Engineer's   Practice. 

Being  a  Short  but  Complete  Description  of  the  Duties  of  the 
Young  Engineer  in  Preliminary  and  Location  Surveys  and  in 
Construction.  Fourth  Edition,  revised  and  enlarged.  Illustrated. 
12mo,  cloth $1 . 50 

CLEVENGER,  S.  R.  A  Treatise  on  the  Method  of  Gov- 
ernment Surveying  as  prescribed  by  the  U.  S.  Congress  and  Com- 
missioner of  the  General  Land  Office,  with  complete  Mathemati- 
cal, Astronomical,  and  Practical  Instructions  for  the  use  of  the 
United  States  Surveyors  in  the  field.  16mo,  morocco $2 . 50 

CLOUTH,   F.     Rubber,   Gutta-Percha,   and  Balata.     First 

English  Translation  with  Additions  and  Emendations  by  the 
Author.  With  numerous  figures,  tables,  diagrams,  and  folding 
plates.  8vo,  cloth,  illustrated net,  $5.00 

COFFIN,  J.  H.  C.,  Prof.  Navigation  and  Nautical  Astron- 
omy. Prepared  for  the  use  of  the  U.  S.  Naval  Academy.  New 
Edition.  Revised  by  Commander  Charles  Belknap.  52  woodcut 
illustrations.  12mo,  cloth net,  $3 . 50 

COLE,  R.  S.,  M.A.     A  Treatise  on  Photographic  Optics. 

Being  an  account  of  the  Principles  of  Optics,  so  far  as  they  apply 
to  photography.  12mo,  cloth,  103  illus.  and  folding  plates.  .$2.50 

COLLINS,  J.  E.  The  Private  Book  of  Useful  Alloys  and 
Memoranda  for  Goldsmiths,  Jewelers,  etc.  18mo,  cloth SO .  50 

COLLINS,  T.  B.     The  Steam  Turbine,  or  the  New  Engine. 

8vo,  cloth,  illustrated In  Press. 

COOPER,  W.  R.,  M.A.  Primary  Batteries:  Their  Con- 
struction and  Use.  With  numerous  figures  and  diagrams.  8vo, 
cloth,  illustrated net,  $4 . 00" 

COPPERTHWAITE,    WM.    C.     Tunnel   Shields,    and   the 

Use  of  Compressed  Air  in  Subaqueous  Works.  With  numerous 
diagrams  and  figures.  4to,  cloth,  illustrated net,  $9.00 

COREY,  H.  T.   Water-supply  Engineering.   Fully  illustrated. 

In  Press. 

CORNWALL,  H.  B.,  Prof.  Manual  of  Blow-pipe  Analysis, 
Qualitative  and  Quantitative.  With  a  Complete  System  of 
Determinative  Mineralogy.  8vo,  cloth,  with  many  illustra- 
tions   $2.50 


SCIENTIFIC  PUBLICATIONS.  13 

COWELL,  W.  fc.  Pure  Air,  Ozone  and  Water.  A  Prac- 
tical Treatise  of  their  Utilization  and  Value  in  Oil,  Grease,  Soap. 
Paint,  Glue  and  other  Industries.  With  tables  and  figures. 
12mo,  cloth,  illustrated net,  $2 . 00 

CRAIG,  B.  F.     Weights  and  Measures.    An  Account  of 

the  Decimal  System,  with  Tables  of  Conversion  for  Commercial 
and  Scientific  Uses.  Square  32mo,  limp  cloth 50 

CROCKER,  F.  B.,  Prof.     Electric   Lighting.     A  Practical 

Exposition  of  the  Art.  For  use  of  Engineers,  Students,  and 
others  interested  in  the  Installation  or  Operation  of  Electrical 
Plants.  Vol.  I.  The  Generating  Plant.  New  Edition,  thoroughly 

revised  and  rewritten.     8vo,  cloth,  illustrated $3 .00 

Vol.  II.  Distributing  Systems  and  Lamps.  Fifth  Edition.  8vo, 
cloth,  illustrated $3 .00 

• and  WHEELER,  S.  S.    The  Management  of  Electrical 

Machinery.  Being  a  thoroughly  revised  and  rewritten  edition  of 
the  authors'- "Practical  Management  of  Dynamos  and  Motors." 
With  a  special  chapter  by  H.  A.  Foster.  12mo,  cloth,  illustrated. 

net,  $1.00 

CROSSKEY,  L.  R.     Elementary  Perspective:   Arranged  to 

meet  the  requirements  of  Architects  and  Draughtsmen,  and  of 
Art  Students  preparing  for  the  elementary  examination  of  the 
Science  and  Art  Department,  South  Kensington.  With  numer- 
ous full-page  plates  and  diagrams.  8vo,  cloth,  illustrated  .  .  $1 .00 

and  THAW.,  J.     Advanced  Perspective,  involving  the 

Drawing  of  Objects  when  placed  in  Oblique  Positions,  Shadows 
and  Reflections.  Arranged  to  meet  the  requirements  of  Archi- 
tects, Draughtsmen,  and  Students  preparing  for  the  Perspective 
Examination  of  the  Education  Department.  With  numerous  full- 
page  plates  and  diagrams.  8vo.  cloth,  illustrated $1 . 50 

DAVIES,    E.    H.     Machinery    for    Metalliferous    Mines. 

A  Practical  Treatise  for  Mining  Engineers,  Metallurgists  and 
Managers  of  Mines.  With  upwards  of  400  illustrations.  Second 
Edition,  rewritten  and  enlarged.  8vo,  cloth net,  $8 . 00 

DAVIES,  D.  C.     A  Treatise  on  Metalliferous  Minerals  and 

Mining.  Sixth  Edition,  thoroughly  revised  and  much  enlarged  by  his 
eon.  8vo,  cloth net,  $5.00 

-  Mining  Machinery In  Press. 

DAVISON,  G.  C.,  Lieut.     Water-tube  Boilers In  Press. 


14  D.  VAN  NOSTRAND  COMPANY'S 

DAY,  C.     The  Indicator  and  its  Diagrams.     With  Chap 

ters  on  Engine  and  Boiler  Testing;  including  a  Table  of  Piston 
Constants  compiled  by  W.  H.  Fowler.  12mo,  cloth.  125  illus- 
trations   $2.00 

DEITE,  Dr.  C.  Manual  of  Soapmaking,  including  medi- 
cated soaps,  stain-removing  soaps,  metal  polishing  soaps,  soap 
powders  and  detergents.  With  a  treatise  on  perfumes  for  scented 
soaps,  and  their  production  and  tests  for  purity  and  strength. 
Edited  from  the  text  of  numerous  experts.  Translated  from  the 
original  by  S.  I.  King,  F.C.S.  With  figures.  4to,  cloth,  illustrated. 

net,  $5.00 

DE  LA  COUX,  H.     The  Industrial  Uses  of  Water.     With 

numerous  tables,  figures,  and  diagrams.  Translated  from  the 
French  and  revised  by  Arthur  Morris.  8vo,  cloth net,  $4 . 50 

DENNY,  G.  A.     Deep-level  Mines  of  the  Rand,  and  their 

future  development,  considered  from  the  commercial  point  of 
view.  With  folding  plates,  diagrams,  and  tables.  4to,  cloth, 
illustrated net,  $10 . 00 

DERR,    W.    L.     Block    Signal    Operation.     A    Practical 

Manual.     Pocket  Size.     Oblong,  cloth.     Second  Edition.  .  .  .$1 .50 

DIBDIN,  W.  J.     Public  Lighting  by  Gas  and  Electricity. 

With  tables,  diagrams,  engravings  and  full-page  plates.  8vo, 
cloth,  illustrated. net,  $8 . 00 

—  Purification    of    Sewage    and   Water.      With    tables, 

engravings,  and  folding  plates.  Third  Edition,  revised  and 
enlarged.  8vo,  cloth,  illus.  and  numerous  folding  plates.  ...  $6. 50 

DIETERICH,  K.    Analysis  of  Resins,  Balsams,  and  Gum 

Resins:  their  Chemistry  and  Pharmacognosis.  For  the  use  of 
the  Scientific  and  Technical  Research  Chemist.  With  a  Bibliog- 
raphy. Translated  from  the  German,  by  Chas.  Salter.  8vo. 
cloth net,  $3 .00 

DIXON,    D.    B.     The   Machinist's   and   Steam   Engineer's 

Practical  Calculator.  A  Compilation  of  Useful  Rules  and  Prob- 
lems arithmetically  solved,  together  with  General  Information 
applicable  to  Shop-tools,  Mill-gearing,  Pulleys  and  Shafts,  Steam- 
boilers  and  Engines.  Embracing  valuable  Tables  and  Instruc- 
tion in  Screw-cutting,  Valve  and  Link  Motion,  etc.  Third  Edition. 
16mo,  full  morocco,  pocket  form $1 . 25 

DOBLE,  W.  A.     Power  Plant  Construction  on  the  Pacific 

Coast ...  .    In  Press. 


SCIENTIFIC  PUBLICATIONS.  15 

DODD,  GEO.     Dictionary  of  Manufactures,  Mining,  Ma- 
chinery, and  the  Industrial  Arts.     12mo,  cloth $1 . 50 


DORR,  B.  F.  The  Surveyor's  Guide  and  Pocket  Table- 
book.  Fifth  Edition,  thoroughly  revised  and  greatly  extended. 
With  a  second  appendix  up  to  date.  16mo,  morocco  flaps.  .  $2 . 00 

DRAPER,    C.    H.      An    Elementary   Text-book    of   Light, 

Heat  and  Sound,  with  Numerous  Examples.  Fourth  Edition. 
12mo,  cloth,  illustrated $1 . 00 

Heat  and  the  Principles  of  Thermo-dynamics.     With 

many  illustrations  and  numerical  examples.     12mo,  cloth.  . .   $1 . 50 

DYSON,   S.   S.     Practical   Testing   of  Raw  Materials.     A 

Concise  Handbook  for  Manufacturers,  Merchants,  and  Users  of 
Chemicals,  Oils,  Fuels,  Gas  Residuals  and  By-products,  and 
Paper-making  Materials,  with  Chapters  on  Water  Analysis  and 
the  Testing  of  Trade  Effluents.  8vo,  cloth,  illustrations,  177 
pages net,  $5 . 00 

ECCLES,  R.  G.  (Dr.),  and  DUCKWALL,  E.  W.  Food  Pre- 
servatives: their  Advantages  and  Proper  Use;  The  Practical 
•uersus  the  Theoretical  Side  of  the  Pure  Food  Problem.  8vo, 

paper $0 . 50 

Cloth 1 .00 

EDDY,    H.    T.,    Prof.     Researches   in    Graphical    Statics. 

Embracing  New  Constructions  in  Graphical  Statics,  a  New  General 
Method  in  Graphical  Statics,  and  the  Theory  of  Internal  Stress 
in  Graphical  Statics.  8vo,  cloth $1 . 50 

Maximum  Stresses  under  Concentrated  Loads.  Treated 

graphically.     Illustrated.     8vo,  cloth $1 . 50 

EISSLER,  M.     The  Metallurgy  of  Gold.   A  Practical  Treatise 

on  the  Metallurgical  Treatment  of  Gold-bearing  Ores,  including 
the  Processes  of  Concentration  and  Chlorination,  and  the  Assay- 
ing, Melting  and  Refining  of  Gold.  Fifth  Edition,  revised  and 
greatly  enlarged.  Over  300  illustrations  and  numerous  folding 
plates.  8vo,  cloth $7 . 50 

The  Hydro-Metallurgy  of  Copper.     Being  an  Account 

of  processes  adopted  in  the  Hydro-metallurgical  Treatment  of 
Cupriferous  Ores,  including  the  Manufacture  of  Copper  Vitriol. 
With  chapters  on  the  sources  of  supply  of  Copper  and  the  Roasting 
of  Copper  Ores.  With  numerous  diagrams  and  figures.  8vo, 
cloth,  illustrated net,  $4.50 


16  D.  VAN  NOSTRAND  COMPANY'S 

EISSLER,    M.      The   Metallurgy  of    Silver.      A  Practical 

Treatise  on  the  Amalgamation,  Roasting  and  Lixiviation  of  Silver 
Ores,  including  the  Assaying,  Melting  and  Refining^of  Silver 
Bullion.  124  illustrations.  Second  Edition,  enlarged,  ^vo,  cloth. 

$4.00 

-  The  Metallurgy  of  Argentiferous  Lead.     A  Practical 

Treatise  on  the  Smelting  of  Silver-Lead  Ores  and  the  Refining  of 
Lead  Bullion.  Including  Reports  on  Various  Smelting  Establish- 
ments and  Descriptions  of  Modern  Smelting  Furnaces  and  Plants 
in  Europe  and  America.  With  183  illustrations.  8vo,  cloth, 

$5.00 

-Cyanide  Process  for  the  Extraction  of  Gold  and  its 

Practical  Application  on  the  Witwatersrand  Gold  Fields  in  South 
Africa.  Third  Edition,  revised  and  enlarged.  Illustrations  and 
folding  plates.  8vo,  cloth $3 .00 

—  A  Handbook  on  Modern  Explosives.  Being  a  Prac- 
tical Treatise  on  the  Manufacture  and  Use  of  Dynamite,  Gun- 
cotton,  Nitroglycerine,  and  other  Explosive  Compounds,  in- 
cluding the  manufacture  of  Collodion-cotton,  with  chapters  on 
^Explosives  in  Practical  Application.  Second  Edition,  enlarged 
with  150  illustrations.  12mo,  cloth '. $5 . 00 

ELIOT,    C.   W.,    and   STOKER,    F.    H.     A   Compendious. 

Manual  of  Qualitative  Chemical  Analysis.  Revised  with  the  co- 
operation of  the  authors,  by  Prof.  William  R.  Nichols.  Illus- 
trated. Twentieth  Edition,  newly  revised  by  Prof.  W.  B.  Lindsay. 
12mo,  cloth net,  $1 . 25 

ELLIOT,  G.  H.,  Maj.  European  Light-house  Systems. 
Being  a  Report  of  a  Tour  of  Inspection  made  in  1873.  51  en- 
gravings and  21  woodcuts.  8vo,  cloth $5.00 

ERFURT,  J.     Dyeing  of  Paper  Pulp.    A  Practical  Treatise 

for  the  use  of  paper-makers,  paper-stainers,  students  and  others, 
With  illustrations  and  157  patterns  of  paper  dyed  in  the  pulp, 
with  formulas  for  each.  Translated  into  English  and  edited, 
with  additions,  by  Julius  Hiibner,  F.C.S.  8vo,  cloth,  illus- 
trated  net,  $7 . 50 

EVERETT,  J.  D.  Elementary  Text-book  of  Physics. 
Illustrated.  Seventh  Edition.  12mo,  cloth $1 . 50 

EWING,   A.   J.,   Prof.     The   Magnetic   Induction   in   Iron 

and  other  metals.  Third  Edition,  revised.  159  illustrations 
8vo,  cloth $4 . 00 


SCIENTIFIC  PUBLICATIONS.  17 

FAIRIE,  J.,  F.G.S.  Notes  on  Lead  Ores:  Their  Distribu- 
tion and  Properties.  12mo,  cloth $1 . 00 

Notes  on  Pottery  Clays:  The  Distribution,  Properties, 

Uses  and  Analysis  of  Ball  Clays,  China  Clays  and  China  Stone. 
With  tables  and  formulae.  12mo,  cloth $1 . 50 

FANNING,  J.  T.     A  Practical  Treatise  on  Hydraulic  and 

Water-supply  Engineering.  Relating  to  the  Hydrology,  Hydro- 
dynamics and  Practical  Construction  of  Water-works  in  North 
America.  180  illus.  8vo,  cloth.  Sixteenth  Edition,  revised,  en- 
larged, and  new  tables  and  illustrations  added.  650  pp $5 . 00 

FAY,  I.  W.  The  Coal-tar  Colors:  Their  Origin  and  Chem- 
istry. 8vo,  cloth,  illustrated In  Press. 

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GRIFFITHS,   A.   B.,   Ph.D.     A  Treatise   on   Manures,   or 

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i 

GROVER,    F.     Practical    Treatise    on    Modern    Gas    and 

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P.  Powles.  Third  English  Edition,  revised.  8vo,  cloth,  illus- 
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HALL,   C.   H.     Chemistry  of  Paints  and  Paint  Vehicles. 

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22  D.  VAN  NOSTRAND  COMPANY'S 

HALSEY,   F.   A.     Slide-valve   Gears.     An   Explanation   of 

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HAMILTON,    W.    G.     Useful    Information    for    Railway 

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HAMMER,  W.  J.  Radium,  and  Other  Radio-active  Sub- 
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HANCOCK,  H.  Text-book  of  Mechanics  and  Hydro- 
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HARDY,    E.     Elementary   Principles    of   Graphic    Statics. 

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HARRISON,    W.    B.     The    Mechanics'    Tool-book.     With 

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HART,  J.  W.     External  Plumbing  Work.    A  Treatise  on 

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Evaporating,    Condensing    and    Cooling     Apparatus : 

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HAUSNER,    A.     Manufacture    of    Preserved    Foods    and 

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HAWKESWORTH,  J.  Graphical  Handbook  for  Rein- 
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8vo,  cloth In  Press. 


24  D.  VAN  NOSTRAND  COMPANY'S 

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HEAP,    D.    P.,   Major,    U.S.A.      Electrical   Appliances    of 

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HEAVISIDE,    0.     Electromagnetic    Theory.     8vo,    cloth. 

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HECK,  R.  C.  H.     Steam-Engine  and  Other  Steam  Motors. 

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HEDGES,  K.  Modern  Lightning  Conductors.  An  Illus- 
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HEERMANN,   P.     Dyers'   Materials.    An   Introduction   to 

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HERMANN,   F.     Painting    on    Glass   and   Porcelain    and 

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net,  $3 . 50 

HERRMANN,   G.     The   Graphical   Statics   of  Mechanism. 

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SCIENTIFIC  PUBLICATIONS.  25 

HERZFELD,  J.,  Dr.     The  Technical  Testing  of  Yarns  and 

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lated by  Chas.  Salter.     With  69  illustrations.     8vo,  cloth  net,  $3 . 50 

HEWSON,    W.     Principles    and    Practice    of    Embanking 

Lands  from  River  Floods,  as  applied  to  the  Levees  of  the  Missis- 
sippi.    8vo,  cloth $2 . 00 

HILL,  J,  W.     The  Purification  of  Public  Water  Supplies. 

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HIROI,    I.     Statically-Indeterminate    Stresses   in    Frames 

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HOBBS,  W.  R.  P.  The  Arithmetic  of  Electrical  Measure- 
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HOFF,  J.  N.     Paint  and  Varnish  Facts  and  Formulas.    A 

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HOFF,  WM.  B.,  Com.,  U.S.N.  The  Avoidance  of  Collisions 
at  Sea.  18mo,  morocco 75 

HOLLEY,  A.  L.  Railway  Practice.  American  and  Euro- 
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Joint  Fastenings,  Street  Railways,  etc.  With  77  lithographed 
plates.  Folio,  cloth $12 . 00 

HOLMES,  A.  B.     The  Electric  Light  Popularly  Explained. 

Fifth  Edition.     Illustrated.     12mo,  paper .40 

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26  D.  VAN  NOSTRAND  COMPANY'S 

HORNER,  J.  Engineers'  Turning,  in  Principle  and  Prac- 
tice. A  Handbook  for  Working  Engineers,  Technical  Students, 
and  Amateurs.  With  488  figures  and  diagrams.  Svo,  cloth, 
illustrated net,  $3. 50 

HOUSTON,  E.  J.,  and  KENNELLY,  A.  E.     Algebra  Made 

Easy.  Being  a  clear  explanation  of  the  Mathematical  Formulae 
found  in  Prof.  Thompson's  "Dynamo-electric  Machinery  and 
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HOWARD,  C.  R.     Earthwork  Mensuration  on  the  Basis 

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Areas.  Illustrated  by  Examples  and  accompanied  by  Plain 
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HOWORTH,    J.     Art    of   Repairing   and   Riveting   Glass, 

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HUBBARD,  E.  The  Utilization  of  Wood-waste.  A  Com- 
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and  enlarged  edition.  Svo,  cloth,  illustrated,  192  pages.  .  net,  $2.50 

HUMBER,  W.,  C.E.     A  Handy  Book  for  the  Calculation 

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SCIENTIFIC  PUBLICATIONS.  27 

HURST,  G.H.,  F.C.S.     Lubricating  Oils,  Fats  and  Greases: 

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HUTCHINSON,  R.  W.,  Jr.     Long  Distance  Electric  Power 

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BUTTON,  W.  S;     Steam-boiler  Construction.     A  Practical 

Handbook  for  Engineers,  Boiler-makers  and  Steam-users.  Con- 
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The  Works'  Manager's  Handbook   of  Modern  Rules, 

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INGLE,    H.     Manual    of    Agricultural    Chemistry.     8vo, 

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JAMIESON,  A.,  C.E.  A  Text-book  on  Steam  and  Steam- 
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JANNETTAZ,  E.    A  Guide  to  the  Determination  of  Rocks : 

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JEHL,  F.,  Mem.  A.I.E.E.      The  Manufacture  of  Carbons 

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JENNISON,   F.   H.     The   Manufacture   of  Lake  Pigments 

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JOCKIN,  WM.     Arithmetic  of  the  Gold  and  Silversmith. 

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SCIENTIFIC  PUBLICATIONS.  29 

JOHNSON,  W.  McA.    "The  Metallurgy  of  Nickel."  In  Press. 
JOHNSTON,  J.  F.  W.,  Prof.,  and  CAMERON,  Sir  Chas. 

Elements  of  Agricultural  Chemistry  and  Geology.  Seventeenth 
Edition.  12mo,  cloth $2 . 60 

JONES,    H.    C.       Outlines    of    Electrochemistry.      With 

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JOYNSON,    F.    H.     The    Metals    Used    in     Construction. 

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Designing    and    Construction    of   Machine     Gearing. 

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JUPTNER,  H.   F.  V.     Siderology:    The  Science  of  Iron. 

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KANSAS    CITY    BRIDGE,    THE.     With    an    Account    of 

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Methods  used  for  Founding  in  that  River,  by  O.  Chanute,  Chief 
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KAPP,    G.,    C.E.     Electric   Transmission    of   Energy   and 

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Dynamos,  Motors,  Alternators  and  Rotary  Con- 
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H.  Simmons,  A.M. I.E. E.  With  numerous  diagrams  and  figures. 
8vo,  cloth,  507  pages $4 . 00 

KEIM,    A.   W.      Prevention    of    Dampness    in    Buildings. 

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second  revised,  German  edition.  With  colored  plates  and  dia- 
grams. 8vo,  cloth,  illustrated,  115  pages net,  $2.00 

KELSEY,    W.    R.      Continuous-current     Dynamos    and 

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KEMP,  J.  F.,  A.B.,  E.M.  (Columbia  Univ.).     A  Handbook 

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the  names  of  rocks  and  of  other  lithological  terms.  Third  Edition, 
revised.  8vo,  cloth,  illustrated $1 . 50 

KEMPE,   H.   R.     The   Electrical   Engineer's   Pocket-book 

of  Modern  Rules,  Formulae,  Tables  and  Data.  Illustrated. 
32mo,  morocco,  gilt $1 . 75 

KENNEDY,  R.     Modern  Engines  and  Power  Generators. 

A  Practical  Work  on  Prime  Movers  and  the  Transmission  of 
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$15.00 
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Electrical    Installations    of    Electric    Light,   Power, 

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KENNELLY,  A.  E.  Theoretical  Elements  of  Electro- 
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KINGDON,   J.   A.     Applied  Magnetism.     An   Introduction 

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SCIENTIFIC  PUBLICATIONS.  31 

KINZBRUNNER,  C.     Alternate  Current  Windings;    Their 

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and  all  Practical  Men.  8vo,  cloth,  illustrated net,  II  .50 

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Construction.  A  Handbook  for  Students,  Designers,  and  all 
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KIRKALDY,    W.    G.    Illustrations    of    David    Kirkaldy's 

System  of  Mechanical  Testing,  as  Originated  and  Carried  on  by 
him  during  a  Quarter  of  a  Century.  Comprising  a  Large  Selec- 
tion of  Tabulated  Results,  showing  the  Strength  and  other  Proper- 
ties of  Materials  used  in  Construction,  with  Explanatory  Text 
and  Historical  Sketch.  Numerous  engravings  and  25  lithographed 
plates.  4to,  cloth $10 .00 

KIRKBRIDE,   J.     Engraving  for  Illustration:    Historical 

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KIRKWOOD,   J.   P.     Report   on   the   Filtration   of  River 

Waters  for  the  Supply  of  Cities,  as  practised  in  Europe,  made 
to  the  Board  of  Water  Commissioners  of  the  City  of  St.  Louis. 
Illustrated  by  30  double-page  engravings.  4to,  cloth  ....  $7.50 

KLEIN,    J.    F.      Design    of    a   High-speed   Steam-engine. 

With  notes,  diagrams,  formulas  and  tables.  Second  Edition, 
revised  and  enlarged.  8vo,  cloth,  illustrated net,  $5 . 00 

KLEINHANS,  F.  B.  Boiler  Construction.  A  Practical  ex- 
planation of  the  best  modern  methods  of  Boiler  Construction, 
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diagrams  and  full-page  engravings.  8vo,  cloth,  illustrated. .$3.00 

KNIGHT,  A.  M.,  Lieut.-Com.  U.S.N.  Modern  Seaman- 
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cloth,  illustrated.     Second  Edition,  revised net,  $6.00 

Half  morocco $7 . 50 

KNOTT,  C.  G.,  and  MACKAY,  J.  S.     Practical  Mathematics. 

With  numerous  examples,  figures  and  diagrams.  New  Edition. 
8vo,  cloth,  illustrated $2 .00 

KOLLER,    T.     The    Utilization    of    Waste    Products.     A 

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32  D.  VAN  NOSTRAND  COMPANY'S 

KOLLER,  T.    Cosmetics.   A  Handbook  of  the  Manufacture, 

Employment  and  Testing  of  all  Cosmetic  Materials  and  Cosmetic 
Specialties.  Translated  from  the  German  by  Chas.  Salter.  8vo. 
cloth net,  $2 . 50 

KRAUCH,    C.,    Dr.     Testing    of    Chemical    Reagents    for 

Purity.  Authorized  translation  of  the  Third  Edition,  by  J.  A. 
Williamson  and  L.  W.  Dupre.  With  additions  and  emendations 
by  the  author.  8vo,  cloth net,  $4 . 50 

LAMBERT,   T.     Lead,  and  its  Compounds.    With  tables, 

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Bone     Products     and     Manures.       An     Account     of 

the  most  recent  improvements  in  the  manufacture  of  Fat,  Glue, 
Ajiimal  Charcoal,  Size,  Gelatine  and  Manures.  With  plans  and 
diagrams.  8vo,  cloth,  illustrated net,  $3 . 00 

LAMBORN,  L.  L.     Cottonseed  Products :  A  Manual  of  the 

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folding  map.  8vo,  cloth,  illustrated net,  $3 .00 

-  Modern  Soaps,  Candles,  and  Glycerin.     A   practical 

manual  of  modern  methods  of  utilization  of  Fats  and  Oils  in  the 
manufacture  of  Soaps  and  Candles,  and  the  recovery  of  Glycerin. 
8vo,  cloth,  illustrated net,  $7 . 50 

LAMPRECHT,    R.     Recovery   Work   after   Pit   Fires.     A 

description  of  the  principal  methods  pursued,  especially  in  fiery 
mines,  and  of  the  various  appliances  employed,  such  as  respira- 
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diagrams.  Translated  from  the  German  by  Charles  Salter.  8vo, 
cloth,  illustrated net,  $4 . 00 

LARRABEE,  C.  S.  Cipher  and  Secret  Letter  and  Tele- 
graphic Code,  with  Hog's  Improvements.  The  most  perfect 
Secret  Code  ever  invented  or  discovered.  Impossible  to  read 
without  the  key.  18mo,  cloth 60 

LASSAR-COHN,  Dr.  An  Introduction  to  Modern  Scien- 
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Extension  Students  and  general  readers.  Translated  from  the 
author's  corrected  proofs  for  the  second  German  edition,  by 
M.  M.  Pattison  Muir,  M.A.  12mo,  cloth,  illustrated $2.00 


SCIENTIFIC  PUBLICATIONS.  33 

LATTA,  M.  N.     Gas  Engineering  Practice.     With  figures, 

diagrams  and  tables,     bvo,  cloth,  illustrated in  Press. 

LEASK,  A.  R.     Breakdowns  at  Sea  and  How  to  Repair 

Them.     With  89  illustrations.     Second  Edition.     8vo,  cloth.  $2.00 

Triple  and  Quadruple  Expansion  Engines  and  Boilers 

and  their  Management.  With  59  illustrations.  Third  Edition, 
revised.  12mo,  cloth $2 . 00 

Refrigerating  Machinery:  Its  Principles  and  Man- 
agement. With  64  illustrations.  12mo,  cloth $2.00 

LECKY,    S.    T.    S.     "Wrinkles"   in   Practical   Navigation. 

With  130  illustrations.  8vo,  cloth.  Fourteenth  Edition,  revised 
and  enlarged $8 . 00 

LEFEVRE,  L.     Architectural  Pottery:  Bricks,  Tiles,  Pipes, 

Enameled  Terra-Cottas,  Ordinary  and  Incrusted  Quarries,  Stone- 
ware Mosaics,  Faiences  and  Architectural  Stoneware.  With 
tables,  plates  and  950  cuts  and  illustrations.  With  a  preface  by 
M.  J.-C.  Formige.  Translated  from  the  French,  by  K.  H.  Bird, 
M.A.,  and  W.  Moore  Binns.  4to,  cloth,  illustrated net,  $7.50 

LEHNER,  S.  Ink  Manufacture :  including  Writing,  Copy- 
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lated from  the  fifth  German  edition,  by  Arthur  Morris  and 
Herbert  Robson,  B.Sc.  8vo,  cloth,  illustrated net,  $2.50 

LEMSTROM,  Dr.  Electricity  in  Agriculture  and  Horticul- 
ture. Illustrated net,  $1 . 50 

LEVY,  C.  L.  Electric-light  Primer.  A  simple  and  com- 
prehensive digest  of  all  the  most  important  facts  connected  with 
the  running  of  the  dynamo,  and  electric  lights,  with  precautions 
for  safety.  For  the  use  of  persons  whose  duty  it  is  to  look  after 
the  plant.  8vo,  paper 50 

LIVERMORE,  V.  P.,  and  WILLIAMS,  J.     How  to  Become 

a  Competent  Motorman.  Being  a  Practical  Treatise  on  the 
Proper  Method  of  Operating  a  Street  Railway  Motor  Car;  also 
giving  details  how  to  overcome  certain  defects.  16mo,  cloth, 
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34  D.  VAN  NOSTRAND  COMPANY'S 

LOBBEN,  P.,  M,E.  Machinists*  and  Draftsmen's  Hand- 
book, containing  Tables,  Rules,  and  Formulas,  with  numerous 
examples,  explaining  the  principles  of  mathematics  and  mechanics, 
as  applied  to  the  mechanical  trades.  Intended  as  a  reference  book 
for  all  interested  in  Mechanical  work.  Illustrated  with  many 
cuts  and  diagrams.  8vo,  cloth $2 . 50 

LOCKE,  A.  G.   and  C.  G.     A  Practical    Treatise  on   the 

Manufacture  of  Sulphuric  Acid.  With  77  constructive  plates, 
drawn  to  scale  measurements,  and  other  illustrations.  Royal 
8vo,  cloth.  $10 . 00 

LOCKERT,  L.     Petroleum  Motor-cars.     i2mo,  cloth,  $1.50 

LCCKWOOD,  T.  D.  Electricity,  Magnetism,  and  Electro- 
telegraphy.  A  Practical  Guide  for  Students,  Operators,  and 
Inspectors.  8vo,  cloth .  Third  Edition $2 . 50 

Electrical  Measurement  and  the  Galvanometer:    its 

Construction  and  Uses.  Second  Edition.  32  illustrations.  12mo, 
cloth $1 .50 

LODGE,  0.  J.  Elementary  Mechanics,  including  Hydro- 
statics and  Pneumatics.  Revised  Edition.  12mo,  cloth  ...  $1 . 50 

-Signalling  Across   Space,   Without   Wires:     being   a 

description  of  the  work  of  Hertz  and  his  successors.  With  numer- 
ous diagrams  and  half-tone  cuts,  and  additional  remarks  con- 
cerning the  application  'to  Telegraphy  and  later  developments. 
Third  Edition.  8vo,  cloth,  illustrated net,  $2. 00 

LORD,  R.  T.     Decorative  and  Fancy  Fabrics.     A  Valuable 

Book  with  designs  and  illustrations  for  manufacturers  and  de- 
signers of  Carpets,  Damask,  Dress  and  all  Textile  Fabrics.  8vo, 
cloth,  illustrated net,  $3 . 50 

LORING,   A.   E.     A   Handbook   of   the   Electro-magnetic 

Telegraph.     16mo,  cloth,  boards.     New  and  enlarged  edition.  .    .50 

LUCE,  S.  B.  (Com.,  U.  S.  N.).     Text-book  of  Seamanship. 

The  Equipping  and  Handling  of  Vessels  under  Sail  or  Steam. 
For  the  use  of  the  U.  S.  Naval  Academy.  Revised  and  enlarged 
edition,  by  Lieut.  Wm.  S.  Benson.  8vo,  cloth,  illustrated. $10. 00 

LUCKE,   C.   E.     Gas  Engine   Design.     With  figures  and 

diagrams.     Second  Edition,  revised.     8vo,  cloth,  illustrated. 

net ,  $3 . 00 

Power,   Cost   and  Plant  Designs   and   Construction. 

In  Press. 


SCIENTIFIC  PUBLICATIONS.  35 

LUCKE,  C.  E.     Power  Plant  Papers.     Form  I.     The  Steam 

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LUNGE,   G.,   Ph.D.      Coal-tar  and  Ammonia:    being  the 

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MACKIE,   JOHN.     How   to   Make    a   Woolen   Mill   Pay. 

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36  D.  VAN  NOSTRAND  COMPANY'S 

MAGUTRE,    WM.    R.     Domestic    Sanitary    Drainage    and 

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SCIENTIFIC  PUBLICATIONS.  37 

McNEILL,    B.     McNeilPs    Code.     Arranged    to    meet    the 

requirements  of  Mining,  Metallurgical  and  Civil  Engineers,  Direc- 
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With  tables,  folding  plates  and  numerous  full-page  diagrams 
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MERCK,  E.     Chemical  Reagents :  Their  Purity  and  Tests. 

In  Press. 

MERRITT,  WM.  H.     Field  Testing  for  Gold  and  Silver. 

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METAL  TURNING.  By  a  Foreman  Pattern-maker.  Illus- 
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MICHELL,  S.  Mine  Drainage:  being  a  Complete  Prac- 
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MIERZINSKI,  S.,  Dr.  Waterproofing  of  Fabrics.  Trans- 
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With  diagrams  and  figures.  8vo,  cloth,  illustrated.  .  .  net,  $2.50 

MILLER,  E.  H.  (Columbia  Univ.).     Quantitative  Analysis 

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MINIFIE,    W.     Mechanical    Drawing.     A    Text-book    of 

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are  avoided  as  much  as  possible.  With  illustrations  for  drawing 
Plans,  Sections,  and  Elevations  of  Railways  and  Machinery;  an 
Introduction  to  Isometrical  Drawing,  and  an  Essay  on  Linear 
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38  D.  VAN  NOSTRAND  COMPANY'S 

MINIFIE,  W.     Geometrical  Drawing.     Abridged  from  the 

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plates.  Ninth  Edition.  12mo,  cloth $2 . 00 

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1870.  Illustrated.  12mo,  cloth $1 .50 

MOORE,  E.  C.  S.  New  Tables  for  the  Complete  Solu- 
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open  channels,  pipes,  sewers  and  conduits.  In  two  parts.  Part  I, 
arranged  for  1080  inclinations  from  1  over  1  to  1  over  21,120  for 
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values  of  (n).  With  large  folding  diagram.  8vo,  cloth,  illus- 
trated  net,  $5 . 00 

MOREING,  C.  A.,  and  NEAL,  T.     New  General  and  Mining 

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agents,  and  trust  and  finance  companies.  Eighth  Edition.  8vo, 
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MOSES,  A.  J.  The  Characters  of  Crystals.  An  Intro- 
duction to  Physical  Crystallography,  containing  321  illustrations 
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-  and    PARSONS,    C.    L.     Elements    of    Mineralogy, 

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point. Third  Enlarged  Edition.  8vo,  cloth,  336  illustrations, 

net,  $2.50 

MOSS,  S.  A.     Elements  of  Gas  Engine  Design.    Reprint 

of  a  Set  of  Notes  accompanying  a  Course  of  Lectures  delivered 
at  Cornell  University  in  1902.  16mo,  cloth,  illustrated.  (Van 
Nostrand's  Science  Series) $0.50 

MOSS,  S.  A.     The  Lay-out  of  Corliss  Valve  Gears.     (Van 

Nostrand's  Science  Series.)     16mo,  cloth,  illustrated $0.50 

MULLIN,  J.  P.,  M.E.  Modern  Moulding  and  Pattern- 
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Work:  embracing  the  Moulding  of  Pulleys,  Spur  Gears,  Worm 
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for  every-day  use  in  the  Drawing  Office,  Pattern-shop  and  Foundry. 
12mo,  cloth,  illustrated $2 . 50 


SCIENTIFIC  PUBLICATIONS.  39 

MUNRO,  J.,  C.E.,  and  JAMIESON,  A.,  C.E.  A  Pocket- 
book  of  Electrical  Rules  and  Tables  for  the  use  of  Electricians 
and  Engineers.  Fifteenth  Edition,  revised  and  enlarged.  With 
numerous  diagrams.  Pocket  size.  Leather $2 . 50 

MURPHY,  J.  G.,  M.E.     Practical  Mining.     A  Field  Manual 

for  Mining  Engineers.  With  Hints  for  Investors  in  Mining 
Properties.  16mo,  cloth $1 .00 

NAQUET,  A.     Legal  Chemistry.    A  Guide  to  the  Detection 

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and  Pharmaceutical  Substances,  Analysis  of  Ashes,  and  Exami- 
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Jurisprudence,  for  the  use  of  Chemists,  Physicians,  Lawyers, 
Pharmacists  and  Experts.  Translated,  with  additions,  including 
a  list  of  books  and  memoirs  on  Toxicology,  etc.,  from  the  French, 
by  J.  P.  Battershall,  Ph.D.,  with  a  Preface  by  C.  F.  Chandler, 
Ph.D.,  M.D.,  LL.D.  12mo,  cloth $2.00 

NASMITH,    J.     The    Student's    Cotton    Spinning.     Third 

Edition,  revised  and  enlarged.  8vo,  cloth,  622  pages,  250  illus- 
trations   $3 . 00 

NEUBURGER,    H.,    and   NOALHAT,    H.     Technology    of 

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and  Sea.  Storage  of  Petroleum.  With  153  illustrations  and  25 
plates.  Translated  from  the  French,  by  John  Geddes  Mclntosh. 
8vo,  cloth,  illustrated net,  $10 . 00 

NEW  ALL,  J.  W.     Plain  Practical  Directions  for  Drawing, 

Sizing  and  Cutting  Bevel-gears,  showing  how  the  Teeth  may 
be  cut  in  a  Plain  Milling  Machine  or  Gear  Cutter  so  as  to  give 
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out  all  particulars  for  the  Workshop  without  making  any  Draw- 
ings. Including  a  Full  Set  of  Tables  of  Reference.  Folding 
plates.  8vo,  cloth $1 . 50 

NEWLANDS,  J.     The  Carpenters1  and  Joiners*  Assistant: 

being  a  Comprehensive  Treatise  on  the  Selection,  Preparation 
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Framing,  with  their  application  in  Carpentry,  Joinery  and 
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Illustrated.  Folio,  half  morocco $15.00 


40  D.  VAN  NOSTRAND  COMPANY'S 

NIPHER,  F.  E.,  A.M.     Theory  of  Magnetic  Measurements, 

with  an  Appendix  on  the  Method  of  Least  Squares.  12mo, 
cloth $1.00 

NOLL,  AUGUSTUS.     How  to  Wire  Buildings:    A  Manual 

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Edition.  8vo,  cloth,  illustrated $1 . 50 

NUGENT,   E.     Treatise   on   Optics;    or,   Light   and   Sight 

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O'CONNOR,  H.  The  Gas  Engineer's  Pocket-book.  Com- 
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of  Gas-works.  Second  Edition,  revised.  12mo,  full  leather,  gilt 
edges $3 . 50 

OLSEN,  J.  C.,  Prof.     Text-book  of  Quantitative  Chemical 

Analysis  by  Gravimetric,  Electrolytic,  Volumetric  and  Gasometric 
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With  numerous  figures  and  diagrams.  Second  Edition,  revised. 
8vo,  cloth net,  $4.00 

OSBORN,  F.  C.     Tables  of  Moments  of  Inertia,  and  Squares 

of  Radii  of  Gyration;  supplemented  by  others  on  the  Ultimate 
and  Safe  Strength  of  Wrought-iron  Columns,  Safe  Strength  of 
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Stresses,  Reactions  and  Bending  Moments  in  Swing  Bridges. 
Fifth  Edition.  12mo,  leather net,  $3 . 00 

OUDIN,  M.  A.  Standard  Polyphase  Apparatus  and  Systems. 
With  many  diagrams  and  figures.  Third  Edition,  thoroughly 
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PALAZ,  A.,  Sc.D.     A  Treatise  on  Industrial  Photometry, 

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lation from  the  French  by  George  W.  Patterson,  Jr.  Second 
Edition,  revised.  8vo,  cloth,  illustrated $4.00 

PAMELY,  C.  Colliery  Manager's  Handbook.  A  Compre- 
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SCIENTIFIC  PUBLICATIONS.  41 

* 

PARR,  G.  D.  A.  Electrical  Engineering  Measuring  Instru- 
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PARRY,  E.  J.,  B.Sc.      The  Chemistry  of  Essential  Oils 

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the  more  important  of  the  published  facts  connected  with  the 
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preparation  and  analysis  of  Essential  Oils.  With  numerous  dia- 
grams and  tables.  8vo,  cloth,  illustrated net,  $5 . 00 

-  and  COSTE,  J.  H.      Chemistry  of  Pigments.     With 

tables  and  figures.     8vo,  cloth net,  $4 . 50 

PARRY,  L.  A.,  M.D.     The  Risks  and  Dangers  of  Various 

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PARSHALL,    H.    F.,    and  HOBART,    H.    M.      Armature 

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-  and  PARRY,  E.     Electrical  Equipment  of  Tramways. 

In  Press. 

PASSMORE,  A.  C.     Handbook  of  Technical  Terms  used 

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jects. 8vo,  cloth net,  $3 . 50 

PATERSON,  D.,  F.C.S.  The  Color  Printing  of  Carpet 
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PATTEN,    J.      A   Plan   for   Increasing   the    Humidity   of 

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42  D.  VAN  NOSTRAND  COMPANY'S 

PATTON,    H.     B.      Lecture    Notes    on     Crystallography 

Revised  Edition,  largely  rewritten.  Prepared  for  use  of  the  stu- 
dents at  the  Colorado  School  of  Mines.  With  blank  pages  for 
note-taking.  8vo,  cloth net  $1 . 25 

PAULDING,  C.  P.  Practical  Laws  and  Data  on  the  Con- 
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PEIRCE,     B.       System     of     Analytic     Mechanics.       4to, 

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PERRINE,  F.  A.  C.,  A.M.,  D.Sc.  Conductors  for  Elec- 
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PERRY,  J.      Applied  Mechanics.     A  Treatise  for  the  Use 

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PHIN,  J.     Seven  Follies  of  Science.     A  Popular  Account 

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SCIENTIFIC  PUBLICATIONS.  43 

PICKWORTH,  C.  N.  The  Indicator  Handbook.  A  Prac- 
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Logarithms  for  Beginners.     8vo,  boards $0.50 


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with  Numerous  Rules  and  Practical  Illustrations,  exhibiting  the 
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Plane    Table,    The.      Its   Uses   in   Topographical   Survey- 
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PLATTNER'S    Manual    of    Qualitative    and    Quantitative 

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by  Henry  B.  Cornwall,  E.M.,  Ph.D.,  assisted  by  John  H.  Caswell, 
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PLYMPTON,   GEO.   W.,  Prof.      The  Aneroid  Barometer: 

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POPPLE  WELL,  W.  C.     Elementary  Treatise  on  Heat  and 

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44  D.  VAN  NOSTRAND  COMPANY'S 

POPPLEWELL,  W.  C.     Prevention   of  Smoke,   combined 

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PRAY,  T.,  Jr.     Twenty  Years  with  the  Indicator:    being 

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SCIENTIFIC  PUBLICATIONS.  45 

PRESCOTT,  A.  B.,  Prof.      Outlines  of  Proximate  Organic 

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PULLEN,   W.   W.   F.       Application   of   Graphic  Methods 

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PYNCHON,  T.  R.,  Prof.     Introduction  to  Chemical  Physics, 

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46  D.  VAN  NOSTRAND  COMPANY'S 

RADFORD,  C.  S.,  Lieut.      Handbook  on  Naval  Gunnery. 

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RAM,  G.  S.     The  Incandescent  Lamp  and  its  Manufac- 
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RAMP,  H.  M.     Foundry  Practice In  Press. 

RANDALL,   J.    E.     A   Practical   Treatise    on    the    Incan- 
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RANDA.LL,    P.    M.     Quartz    Operator's   Handbook.     New 

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RANDAU,  P.     Enamels  and  Enamelling.    An  introduction 

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RANKINE,    W.    J.    M.     Applied    Mechanics.     Comprising 

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—  Civil  Engineering.  Comprising  Engineering  Sur- 
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SCIENTIFIC  PUBLICATIONS.  47 

RANKINE,  W.  J.  M.  Machinery  and  Millwork.  Compris- 
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• Useful   Rules  and  Tables  for  Engineers  and  Others. 

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RAPHAEL,    F.    C.     Localization    of    Faults    in    Electric 

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RATEAU,  A.    Experimental  Researches  on  the  Flow  of 

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RAUTENSTRAUCH,  Prof.  W.     Syllabus  of  Lectures  and 

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RAYMOND,  E.  B.  Alternating-current  Engineering  Prac- 
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RAYNER,  H.     Silk  Throwing   and  Waste  Silk  Spinning. 

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48  D.  VAN  NOSTRAND  COMPANY'S 

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REED'S   ENGINEERS'  HANDBOOK  to  the  Local  Marine 

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Key  to  the  Seventeenth  Edition  of  Reed's  Engineers' 

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REED.     Useful  Hints  to  Sea-going  Engineers,  and  How  to 

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REINHARDT,  C.  W.     Lettering  for  Draftsmen,  Engineers, 

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REISER,  F.  Hardening  and  Tempering  of  Steel,  in  Theory 
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cloth,  120  pages $2.50 


SCIENTIFIC  PUBLICATIONS.  49 

REISER,  N.     Faults  in  the  Manufacture  of  Woolen  Goods, 

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RICE,  J.  M.,  and  JOHNSON,  W.  W.     On  a  New  Method 

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ROBERTSON,    L.    S.     Water-tube    Boilers.     Based    on    a 

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ROBINSON,   S.   W.    Practical   Treatise   on  the  Teeth  of 

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ROLLINS,    W.     Notes   on   X-Light.     With    152    full-page 

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50  D    VAN  NOSTRAND  COMPANY'S 

ROSE,  J.,  M.E.     Key  to  Engines  and  Engine-running.     A 

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SAUNDERS,    C.    H.     Handbook    of    Practical    Mechanics 

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SCHELLEN,  H.,  Dr.  Magneto-electric  and  Dynamo- 
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SCIENTIFIC  PUBLICATIONS.  51 

SCHERER,    R.     Casein:    its   Preparation   and   Technical 

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SCHMALL,  C.  N.     First  Course  in  Analytical  Geometry, 

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SCHMALL,  C.  N.,  and  SHACK,  S.  M.     Elements  of  Plane 

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SCHMEER,  LOUIS.     Flow  of  Water:  A   New  Theory  of 

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SCHUMANN,  F.     A  Manual  of  Heating  and  Ventilation 

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SCHWEIZER,  V.  Distillation  of  Resins,  Resinate    Lakes 

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Machines,  Manifplders,  etc.  A  description  of  the  proper  methods 
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nishes, resin-pigments  and  enamel  paints,  the  preparation  of  all 
kinds  of  carbon  pigments,  and  printers'  ink,  lithographic  inks 
and  chalks,  and  also  inks  for  typewriters,  manifolders,  and 
rubber  stamps.  With  tables  and  68  figures  and  diagrams.  8vo, 
cloth,  illustrated net,  $3 . 50 

SCIENCE  SERIES,  The  Van  Nostrand.      (Follows  end  of 

this  list.) 

SCRIBNER,  J.  M.  Engineers'  and  Mechanics'  Com- 
panion. Comprising  United  States  Weights  and  Measures, 
Mensuration  of  Superfices  and  Solids,  Tables  of  Squares  and 
Cubes,  Square  and  Cube  Roots,  Circumference  and  Areas  of 
Circles,  the  Mechanical  Powers.  Centres  of  Gravity,  Gravitation 
of  Bodies,  Pendulums,  Specific  Gravity  of  Bodies,  Strength, 
Weight  and  Crush  of  Materials,  Water-wheels,  Hydrostatic?, 
Hydraulics,  Statics,  Centres  of  Percussion  and  Gyration,  Friction 
Heat,  Tables  of  the  Weight  of  Metals,  Scantling,  etc.,  Steam 
and  Steam-engine.  Twenty-first  Edition,  revised.  16mo,  full 
morocco * $1.50 


52  D.  VAN  NOSTRAND  COMPANY'S 

SEATON,  A.  E.  A  Manual  of  Marine  Engineering.  Com- 
prising the  Designing,  Construction  and  Working  of  Marine 
Machinery.  With  numerous  tables  and  illustrations  reduced  from 
Working  Drawings.  Fifteenth  Edition,  revised  throughout,  with 
an  additional  chapter  on  Water-tube  Boilers.  8vo,  cloth.  $6.00 

and    ROUNTHWAITE,    H.    M.      A   Pocket-book    of 

Marine  Engineering  Rules  and  Tables.  For  the  use  of  Marine 
Engineers  and  Naval  Architects,  Designers,  Draughtsmen,  Super- 
intendents and  all  engaged  in  the  design  and  construction  of 
Marine  Machinery,  Naval  and  Mercantile.  Seventh  Edition, 
revised  and  enlarged.  Pocket  size.  Leather,  with  diagrams.  $3 . 00 

SEIDELL,    A.     Handbook    of    Solubilities.     i2mo,  cloth. 

In  Press. 

SEVER,  G.  F.,  Prof.  Electrical  Engineering  Experi- 
ments and  Tests  on  Direct-current  Machinery.  With  diagrams 
and  figures.  Svo  pamphlet,  illustrated net,  $1 . 00 

-and  TOWNSEND,  F.     Laboratory  and  Factory  Tests 

in  Electrical  Engineering.  Second  Edition.  Svo,  cloth,  illus- 
trated. ..  i net,  $2 . 50 

SEWALL,  C.  H.     Wireless  Telegraphy.     With    diagrams 

and  engravings.  Second  Edition,  corrected.  Svo,  cloth,  illus- 
trated  net,  $2.00 

Lessons    in   Telegraphy.     For   use    as    a    text-book 

in  schools  and  colleges,  or  for  individual  students.  Illustrated. 
12mo,  cloth $1.00 

SEWELL,    T.     Elements    of    Electrical    Engineering.      A 

First  Year's  Course  for  Students.  Second  Edition,  revised,  with 
additional  chapters  on  Alternating-current  Working  and  Ap- 
pendix of  Questions  and  Answers.  With  many  diagrams,  tables 
and  examples.  Svo,  cloth,  illustrated,  432  pages net,  $3 . 00 

SEXTON,  A.  H.  Fuel  and  Refractory  Materials.  Svo, 
cloth $2 . 00 

-  Chemistry  of  the  Materials  of  Engineering.  A  Hand- 
book for  Engineering  Students.  With  tables,  diagrams  and 
illustrations.  12mo,  cloth,  illustrated $2.50 

SEYMOUR,  A.     Practical  Lithography.     With  figures  and 

engravings.     Svo,  cloth,  illustrated net,  $2 . 50 


SCIENTIFIC  PUBLICATIONS.  53 

- 

SHAW,  S.  The  History  of  the  Staffordshire  Potteries,  and 
the  Rise  and  Progress  of  the  Manufacture  of  Pottery  and  Por- 
celain; with  references  to  genuine  specimens,  and  notices  of 
eminent  potters.  A  re-issue  of  the  original  work  published  in 
1829.  8vo,  cloth,  illustrated net,  $3 . 00 

Chemistry    of    the    Several    Natural    and    Artificial 

Heterogeneous  Compounds  used  in  Manufacturing  Porcelain, 
Glass  and  Pottery.  Re-issued  in  its  original  form,  published  in 
1837.  8vo,  cloth net,  $5.00 

SHELDON,  S.,  Ph.D.,  and  MASON,  H.,  B.S.  Dynamo- 
electric  Machinery:  its  Construction,  Design  and  Operation, 
Direct-current  Machines.  Fifth  Edition,  revised.  8vo,  cloth,  il- 
lustrated  net,  $2 . 50 

Alternating-current     Machines:     being    the     second 

volume  of  the  author's  "Dynamo-electric  Machinery:  its  Construc- 
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(Binding  uniform  with  volume  I.)  Fourth,  Edition.  8vo,  cloth, 
illustrated net,  $2. £0 

SHIELDS,  J.  E.  Notes  on  Engineering  Construction. 
Embracing  Discussions  of  the  Principles  involved,  and  Descrip- 
tions of  the  Material  employed  in  Tunneling,  Bridging,  Canal  and 
Road  Building,  etc.  12mo,  cloth $1 . 50 

SHOCK,  W.  H.  Steam  Boilers:  their  Design,  Construc- 
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SHREVE,  S    H.     A  Treatise  on  the  Strength  of  Bridges 

and  Roofs.  Comprising  the  determination  of  algebraic  formulas 
for  strains  in  Horizontal,  Inclined  or  Rafter,  Triangular,  Bow- 
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with  practical  applications  and  examples,  for  the  use  of  Students- 
and  Engineers.  87  woodcut  illustrations.  Fourth  Edition.  8vor 
cloth $3.50 

SHUNK,    W.    F.     The    Field   Engineer.     A   Handy   Book 

of  practice  in  the  Survey,  Location  and  Track-work  of  Railroads, 
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selected,  applicable  to  both  the  Standard  and  Narrow  Gauge, 
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Engineer.  Sixteenth  Edition,  revised  and  enlarged.  With 
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54  D.  VAN  NOSTRAND  COMPANY'S 

SIMMS,  F.  W.     A  Treatise  on  the  Principles  and  Practice 

of  Leveling.  Showing  its  application  to  purposes  of  Railway 
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corrected,  with  the  addition  of  Mr.  Laws'  Practical  Examples  for 
setting  out  Railway  Curves.  Illustrated.  8vo,  cloth $2 . 50 

Practical   Tunneling.     Fourth   Edition,    Revised   and 

greatly  extended.  With  additional  chapters  illustrating  recent 
practice  by  D.  Kinnear  Clark.  With  36  plates  and  other  illustra- 
tions. Imperial  8vo,  cloth $8 . 00 

SIMPSON,  'G.  The  Naval  Constructor.  A  Vade  Mecum 
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Owners,  Marine  Superintendents,  Engineers  and  Draughtsmen. 
12mo,  morocco,  illustrated,  500  pages net,  $5.00 

SLATER,    J.    W.     Sewage     Treatment,    Purification    and 

Utilization.  A  Practical  Manual  for  the  Use  of  Corporations, 
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Chemists,  Manufacturers,  Riparian  Owners,  Engineers  and  Rate- 
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SMITH,  F.  E.     Handbook  for  Mechanics.     i2mo,  cloth, 

illustrated In  Press. 

Mechanics  for  Practical  Men.     8vo,  cloth,  about  400 

pp.,  illustrated In  Press. 

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J.  C.     Manufacture  of  Paint.    A  Practical  Handbook 

for  Paint  Manufacturers,  Merchants  and  Painters  With  60  illus- 
trations and  one  large  diagram.  8vo,  cloth net,  $3 . 00 

SNELL,  A.  T.  Electric  Motive  Power:  The  Transmission 
and  Distribution  of  Electric  Power  by  Continuous  and  Alternate 
Currents.  With  a  Section  on  the  Applications  of  Electricity  to 
Mining  Work.  Second  Edition.  8vo,  cloth,  illustrated. .net,  $4 .00 

SNOW,  W.  G.,  and  NOLAN,  T.     Ventilation  of  Buildings. 

16mo,  cloth.     (Van  Nostrand's  Science  Series.) $0.50 

SODDY,    F.      Radio-Activity:     An     elementary     treatise 

from  the  standpoint  of  the  disintegration  theory.  With  40  figures 
and  diagrams.  8vo,  cloth,  illustrated net ,  $3 . 00 


SCIENTIFIC  PUBLICATIONS.  55 

SOXHLET,  D.  H.  Art  of  Dyeing  and  Staining  Marble, 
Artificial  Stone,  Bone,  Horn,  Ivory  and  Wood,  and  of  imitating 
all  sorts  of  Wood.  A  practical  Handbook  for  the  use  of  Joiners, 
Turners,  Manufacturers  of  Fancy  Goods,  Stick  and  Umbrella 
Makers,  Comb  Makers,  etc.  Translated  from  the  German  by 
Arthur  Morris  and  Herbert  Robson,  B.Sc.  8vo,  cloth,  170 
pages net,  $2 . 50 

SPANG,  H.  W.  A  Practical  Treatise  on  Lightning  Pro- 
tection. With  figures  and  diagrams.  12mo,  cloth $1.00 

SPEYERS,  C.  L.  Text-book  of  Physical  Chemistry. 
8vo,  cloth $2.25 

STAHL,  A.  W.,  and  WOODS  A.  T.  Elementary  Mechan- 
ism. A  Text-book  for  Students  of  Mechanical  Engineering. 
Fifteenth  Edition.  12mo,  cloth $2 . 00 

STALEY,  C.,  and  PIERSON,  G.  S.     The  Separate  System 

of  Sewerage:  its  Theory  and  Construction.  Third  Edition, 
revised  and  enlarged.  With  chapter  on  Sewage  Disposal.  With 
maps,  plates  and  illustrations.  8vo,  cloth $3.00 

STAND  AGE,    H.    C.     Leatherworkers'    Manual:     being   a 

Compendium  of  Practical  Recipes  and  Working  Formulae  for 
Curriers,  Boot-makers,  Leather  Dressers,  Blacking  Manufac- 
turers, Saddlers,  Fancy  Leather  Workers,  and  all  persons  en- 
gaged in  the  manipulation  of  leather.  8vo,  cloth net ,  $3 . 50 

-Sealing  Waxes,  Wafers,   and  Other  Adhesives.     For 

the  Household,  Office,  Workshop  and  Factory.  8vo,  cloth,  96 
pages net,  $2 . 00 

STEWART,  R.  W.  Text-book  of  Heat.  Illustrated.  8vo, 
cloth $1 .00 

Text-book  of  Magnetism  and  Electricity.  160  Illus- 
trations and  numerous  examples.  12mo,  cloth $1 .00 

STILES,    A.     Tables    for    Field    Engineers.     Designed   for 

Use  in  the  Field.  Tables  containing  all  the  Functions  of  a  One 
Degree  Curve,  from  which  a  corresponding  one  can  be  found  for 
any  required  Degree.  Also,  Tables  of  Natural  Sines  and  Tangents. 
12mo,  morocco,  tucks $2  00 


56  D.  VAN  NOSTRAND  COMPANY'S 

STILLMAN,  P.     Steam-engine  Indicator  and  the  Improved 

Manometer  Steam  and  Vacuum  Gauges;  their  Utility  and  Appli- 
cation. New  edition.  12mo,  flexible  cloth $1 .00 

STODOLA,   Dr.  A.     Steam  Turbines.     With  an  appendix 

on  Gas  Turbines,  and  the  future  of  Heat  Engines.  Authorized 
translation  by  Dr.  Louis  C.  Loewenstein  (Lehigh  University). 
With  241  cuts  and  3  lithographed  tables.  8vo,  cloth,  illustrated. 

net,  $4 . 50 

STONE,   R.,   Gen'l.     New  Roads  and  Road  Laws  in  the 

United  States.  200  pages,  with  numerous  illustrations.  12mo, 
cloth $1 .00 

STONEY,  B.  D.     The  Theory  of  Stresses  in  Girders  and 

Similar  Structures.  With  Observations  on  the  Application  of 
Theory  to  Practice,  and  Tables  of  Strength  and  other  Properties 
of  Materials.  New  revised  edition,  with  numerous  additions  on 
Graphic  Statics,  Pillars,  Steel,  Wind  Pressure,  Oscillating  Stresses, 
Working  Loads,  Riveting,  Strength  and  Tests  of  Materials. 
777  pages,  143  illus.  and  5  folding-plates.  8vo,  cloth $12.50 

SUFFLING,  E.  R.     Treatise  on  the  Art  of  Glass  Painting. 

Prefaced  with  a  Review  of  Ancient  Glass.  With  engravings  and 
colored  plates.  8vo,  cloth net,  $3 . 50 

SWEET,  S.  H.  Special  Report  on  Coal,  Showing  its  Dis- 
tribution, Classification,  and  Costs  delivered  over  Different  Routes 
to  Various  Points  in  the  State  of  New  York  and  the  Principal 
Cities  on  the  Atlantic  Coast.  With  maps.  8vo>  cloth. . .  .$3.00 

SWOOPE,  C.  W.  Practical  Lessons  in  Electricity:  Prin- 
ciples, Experiments,  and  Arithmetical  Problems.  An  Elementary 
Text-book.  With  numerous  tables,  formulae,  and  two  large  in- 
struction plates.  8vo,  cloth,  illustrated.  Seventh  Edition.  .net,  $2. 00 

TAILFER,    L.     Practical    Treatise    on    the    Bleaching    of 

Linen  and  Cotton  Yarn  and  Fabrics.  With  tables  and  diagrams. 
Translated  from  the  French  by  John  Geddes  Mclntosh.  8vo, 
cloth,  illustrated net,  $5 . 00 

TEMPLETON,  W.      The  Practical  Mechanic's  Workshop 

Companion.  Comprising  a  great  variety  of  the  most  useful 
rules  and  formulae  in  Mechanical  Science,  with  numerous  tables 
of  practical  data  and  calculated  results  facilitating  mechanical 
operations.  Revised  and  enlarged  by  W.  S.  Hutton.  12mo, 
morocco .  $2 . 00 


SCIENTIFIC  PUBLICATIONS.  57 

THOM,  C.,  and  JONES,  W.  H.     Telegraphic  Connections: 

embracing  Recent  Methods  in  Quadruplex  Telegraphy.     20  full- 
page  plates,  some  colored.     Oblong,  8vo,  cloth $1 .50 


THOMAS,  C.  W.    .Paper-makers'  Handbook.    A  Practical 

Treatise.     Illustrated In  Press. 

THOMPSON,  A.  B.     Oil  Fields  of  Russia  and  the  Russian 

Petroleum  Industry.  A  Practical  Handbook  on  the  Explora- 
tion, Exploitation,  and  Management  of  Russian  Oil  Properties, 
including  Notes  on  the  Origin  of  Petroleum  in  Russia,  a  Descrip- 
tion of  the  Theory  and  Practice  of  Liquid  Fuel,  and  a  Translation 
of  the  Rules  and  Regulations  concerning  Russian  Oil  Properties. 
With  numerous  illustrations  and  photographic  plates  and  a  map 
of  the  Balakhany-Saboontchy-Romany  Oil  Field.  8vo,  cloth, 
illustrated net,  $7 . 50 

THOMPSON,    E.    P.,    M.E.     How    to    Make    Inventions; 

or,  Inventing  as  a  Science  and  an  Art.  A  Practical  Guide  for 
Inventors.  Second  Edition.  8vo,  boards $0 . 50 

Roentgen   Rays   and  Phenomena  of  the  Anode   and 

Cathode.  Principles,  Applications,  and  Theories.  For  Students, 
Teachers,  Physicians,  Photographers,  Electricians  and  others. 
Assisted  by  Louis  M.  Pignolet,  N.  D.  C.  Hodges  and  Ludwig 
Gutmann,  E.E.  With  a  chapter  on  Generalizations,  Arguments, 
Theories,  Kindred  Radiations  and  Phenomena.  By  Professor  Win. 
Anthony.  50  diagrams,  40  half-tones.  8vo,  cloth $1 . 00 


THOMPSpN,   W.   P.     Handbook   of  Patent   Law   of  All 

Countries.     Thirteenth  Edition,  completely  revised,  March,  1905. 
16mo,  cloth $1 . 50 

THORNLEY,  T.  Cotton  Combing  Machines.  With  Nu- 
merous tables,  engravings  and  diagrams.  8vo,  cloth,  illustrated, 
343  pages net,  $3 .00 

THURSO,  J.   W.     Modern  Turbine  Practice  and  Water- 

Power   Plants.     With  eighty-eight   figures   and   diagrams.     8vo, 
cloth,  illustrated net,  $4 .00 

TOCH,  M.  Chemistry  and  Technology  of  Mixed  Paints. 
8vo,  cloth In  Press. 


58  D.  VAN  NOSTRAND  COMPANY'S 

TODD,   J.,   and   WHALL,   W.   B.     Practical   Seamanship 

for  Use  in  the  Merchant  Service:  including  all  ordinary  subjects; 
also  Steam  Seamanship,  Wreck  Lifting,  Avoiding  Collision.  Wire 
Splicing,  Displacement  and  everything  necessary  to  be  known 
by  seamen  of  the  present  day.  Fifth  Edition,  "with  247  illus- 
trations and  diagrams.  8vo,  cloth net,  $7 . 50 

TOMPKINS,    A.    E.     Text-book    of    Marine    Engineering. 

Second  Edition,  entirely  rewritten,  rearranged,  and  enlarged.  With 
over  250  figures,  diagrams,  and  full-page  plates.  8vo,  cloth, 
illustrated net,  $6 . 00 

TOOTHED  GEARING.     A  Practical  Handbook  for  Offices 

and  Workshops.  By  a  Foreman  Patternmaker.  184  illustra- 
tions. 12mo,  cloth $2 . 25 

TRATMAN,  E.   E.   R.      Railway   Track   and  Track-work. 

With  over  200  illustrations.     8vo,  cloth $3 . 00 

TRAVERSE    TABLE,    Showing    Latitude    and    Departure 

for  each  Quarter  Degree  of  the  Quadrant,  and  for  Distances  from  1 
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gents for  each  five  minutes  of  the  Quadrant.  (Reprinted  from 
Scribner's  Pocket  Table  Book.)  Van  Nostrand's  Science  Series. 

16mo,  cloth $0.50 

Morocco $1 . 00 

TRINKS,  W.,  and  HOUSUM,  C.     Shaft  Governors.     i6mo, 

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TUCKER,  J.  H.,  Dr.  A  Manual  of  Sugar  Analysis,  in- 
cluding the  Applications  in  General  of  Analytical  Methods  to  the 
Sugar  Industry.  With  an  Introduction  on  the  Chemistry  of 
Cane-sugar,  Dextrose,  Levulose,  and  Milk-sugar.  Sixth  Edition. 
8vo,  cloth,  illustrated $3 . 50 

TUMLIRZ,  0.,  Dr.     Potential  and  its  Application  to  the 

Explanation  of  Electrical  Phenomena,  Popularly  Treated.  Trans- 
lated from  the  German  by  D.  Robertson.  12mo,  cloth,  ill.  $1.25 

TUNNER,  P.  A.  Treatise  on  Roll-turning  for  the  Manu- 
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the  Pennsylvania  Steel  Works,  with  numerous  engravings,  wood- 
cuts. 8vo,  cloth,  with  folio  atlas  of  plates $10.00 

TURBAYNE,  A.  A.  Alphabets  and  Numerals.  With  27 
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SCIENTIFIC  PUBLICATIONS.  59 

UNDERBILL,    C.    R.     The    Electro-magnet.     New    and 

revised  edition.     8vo,  cloth,  illustrated net ,  $1 . 50 

URQUHART,  J.  W.     Electric  Light  Fitting.     Embodying 

Practical  Notes  on  Installation  Management.  A  Handbook  for 
Working  Electrical  Engineers.  With  numerous  illustrations. 
12mo,  cloth .  $2 . 00 


Electro-plating.  A  Practical  Handbook  on  the  Depo- 
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num, etc.  Fourth  Edition.  12mo $2 . 00 

Electrotyping.    A  Practical  Manual  Forming  a  New 

and  Systematic  Guide  to  the  Reproduction  and  Multiplication  of 
Printing  Surfaces,  etc.  12mo $2.00 

Electric  Ship  Lighting.     A  Handbook  on  the  Practical 

Fitting  and  Running  of  Ship's  Electrical  Plant.  For  the  Use  of 
Ship  Owners  and  Builders,  Marine  Electricians  and  Sea-going 
Engineers-in-Charge.  Illustrated.  12mo,  cloth $3.00 

UNIVERSAL    TELEGRAPH    CIPHER    CODE.    Arranged 

for  General  Correspondence.     12mo,  cloth $1 .00 

VAN   NOSTRAND'S   Chemical  Annual,  based   on   Bieder- 

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Engineering  Magazine.     Complete  Sets,  1869  to  1886 

inclusive.     35  vols.,  in  cloth $60.00 

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Year  Book  of  Mechanical  Engineering  Data.     With 

many  tables  and  diagrams.     (First  Year  of  issue  1906.)    In  Press. 

VAN   WAGENEN,   T.   F.     Manual   of  Hydraulic   Mining. 

For  the  Use  of  the  Practical  Miner.  Revised  and  enlarged  edition. 
18mo,  cloth $1 .00 

VILLON,  A.  M.  Practical  Treatise  on  the  Leather  Industry. 
With  many  tables  and  illustrations  and  a  copious  index.  A  trans- 
lation of  Villon's  "Traite  Pratique  de  la  Fabrication  des  Cuirs  et 
du  Travail  des  Peaux,"  by  Frank  T.  Addyman,  B.Sc.  8vo, 
cloth,  illustrated net,  $10.00 


60  D.  VAN  NOSTRAND  COMPANY'S 

VINCENT,     C.      Ammonia    and    its    Compounds:      their 

Manufacture  and  Uses.  Translated  from  the  French  by  M.  J. 
Salter.  8vo,  cloth,  illustrated net,  $2.00 

VOLK,    C.     Haulage    and    Winding    Appliances    Used    in 

Mines.  With  plates  and  engravings.  Translated  from  the  Ger- 
man. 8vo,  cloth,  illustrated net,  $4 . 00 

VON  GEORGIEVTCS,  G.     Chemical  Technology  of  Textile 

Fibres:  their  Origin,  Structure,  Preparation,  Washing,  Bleaching, 
Dyeing,  Printing,  and  Dressing.  Translated  from  the  German 
by  Charles  Salter.  With  many  diagrams  and  figures.  8vo,  cloth, 

illustrated.     306  pages net,  $4 . 50 

Contents. — The  Textile  Fibres;  Washing,  Bleaching,  and  Car- 
bonizing; Mordants  and  Mordanting;  Dyeing,  Printing,  Dressing 
and  Finishing;  Index. 

—  Chemistry  of  Dyestuffs.     Translated  from  the  Second 

German  edition  by  Chas.  Salter.     8vo,  cloth,  412  pages. .  .   net,  $4 . 50 

WABNER,    R.     Ventilation    in    Mines.     Translated    from 

the  German  by  Charles  Salter.  With  plates  and  engravings. 
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WADE,  E.  J.  Secondary  Batteries:  their  Theory,  Con- 
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SCIENTIFIC  PUBLICATIONS.  61 

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WEALE,  J.    A  Dictionary  of  Terms  Used  in  Architecture, 

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64  D.  VAN  NOSTRAND  COMPANY'S 

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SCIENTIFIC  PUBLICATIONS.  65 

, 

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tables  of  the  Ultimate  and  Actual  Thrust.  8vo,  half  morocco. 
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WRIGHT,   T.  W.,   Prof.     (Union    College.)     Elements   of 

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-  and  HAYFORD,  J.  F.     Adjustment  of  Observations 

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YOUNG,  J.  E.     Electrical  Testing  for  Telegraph  Engineers. 

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YOUNG   SEAMAN'S    MANUAL.     Compiled   from   Various 

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Marine  Schools.  8vo,  half  roan $3 .00 

ZEUNER,  A.,  Dr.  Technical  Thermodynamics.  Trans- 
lated from  the  German,  by  Prof.  J.  F.  Klein,  Lehigh  University. 
8vo,  cloth,  illustrated In  Press. 

ZIMMER,  G.  F.  Mechanical  Handling  of  Material.  Be- 
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ber, etc.,  by  automatic  and  semi-automatic  machinery,  together 
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ZIPSER,  J.     Textile  Raw  Materials,  and  Their  Conversion 

into  Yarns.  The  study  of  the  Raw  Materials  and  the  Technology 
of  the  Spinning  Process.  A  Text-book  for  Textile,  Trade  and 
higher  Technical  Schools,  as  also  for  self -instruction.  Based  upon 
the  ordinary  syllabus  and  curriculum  of  the  Imperial  and  Royal 
Weaving  Schools.  Translated  from  the  German  by  Chas.  Salter. 
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Catalogue  of  the  Van  Nostrand 
Science  Series. 


*1HHEY  are  put  up  in  a  uniform,  neat,  and  attractive  form.     i8mo, 
boards.      Price  50  cents  per  volume.      The  subjects  are  of  an 
eminently  scientific  character  and  embrace  a  wide  range  of  topics,  and 
are  amply  illustrated  when  the  subject  demands. 

No.  i.  CHIMNEYS  FOR  FURNACES  AND  STEAM  BOILERS.  By 
R.  Armstrong,  C.E.  Third  American  Edition.  Revised  and 
partly  rewritten,  with  an  Appendix  on  "Theory  of  Chimney 
Draught,"  by  F.  E.  Idell,  M.E. 

Wo.  2.  STEAM-BOILER  EXPLOSIONS.  By  Zerah  Colburn.  New 
Edition,  revised  by  Prof.  R.  H.  Thurston. 

Wo.  3.  PRACTICAL  DESIGNING  OF  RETAINING-WALLS.  Fourth 
edition,  by  Prof.  W.  Cain. 

Wo.  4.  PROPORTIONS  OF  PINS  USED  IN  BRIDGES.  By  Charles 
E.  Bender,  C.E.  Second  edition,  with  Appendix. 

Ko.  5.  VENTILATION  OF  BUILDINGS.  By  Wm.  G.  Snow,  S.B.,  and 
Thos.  Nolan,  A.M. 

No.  6.  ON  THE  DESIGNING  AND  CONSTRUCTION  OF  STORAGE 
Reservoirs.  By  Arthur  Jacob,  B.A.  Third  American  edition, 
revised,  with  additions  by  E.  Sherman  Gould. 

No.  7.  SURCHARGED  AND  DIFFERENT  FORMS  OF  RETAINING- 

walls.     By  James  S.  Tate,  C.E. 

Wo.  8.  A  TREATISE  ON  THE  COMPOUND  STEAM-ENGINE.  By 
John  Turnbull,  Jr.  2nd  edition,  revised  by  Prof.  S.  W.  Robinson. 

Wo.  9.  A  TREATISE  ON  FUEL.  By  Arthur  V.  Abbott,  C.E.  Founded 
on  the  original  treatise  of  C.  William  Siemens,  D.C.L.  Third  ed. 

Wo.  10.  COMPOUND  ENGINES.  Translated  from  the  French  of  A. 
Mallet.  Second  edition,  revised  with  results  of  American  Prac- 
tice, by  Richard  H.  Buel,  C.E. 

Wo.  ii.  THEORY  OF  ARCHES.     By  Prof.  W.  Allan. 

Wo.  12.  THEORY  OF  VOUSSOIR  ARCHES.  By  Prof.  Wm.  Cain. 
Third  edition,  revised  and  enlarged. 

Wo.  13.  GASES  MET  WITH  IN  COAL  MINES.  By  J.  J.  Atkinson. 
Third  edition,  revised  and  enlarged,  to  which  is  added  The  Action 
of  Coal  Dusts  by  Edward  H.  Williams,  Jr. 


D.  VAN  NOSTRAND  CO.'S  SCIENTIFIC  PUBLICATIONS 

No.  14.  FRICTION  OF  AIR  IN  MINES.  By  J.  J.  Atkinson.  Second 
American  edition. 

No.  15.  SKEW  ARCHES.  By  Prof.  E.  W.  Hyde,  C.E.  Illustrated. 
Second  edition. 

No.  16.  GRAPHIC  METHOD  FOR  SOLVING  CERTAIN  QUESTIONS 
in  Arithmetic  or  Algebra.  By  Prof.  G.  L.  Vose.  Second 
edition. 

No.  17.  WATER  AND  WATER-SUPPLY.  By  Prof.  W.  H.  Corfield, 
of  the  University  College,  London.  Second  American  edition. 

No.  18.  SEWERAGE   AND    SEWAGE   PURIFICATION.     By    M.    N. 

Baker,  Associate  Editor  "Engineering  News."     Second  edition, 
revised  and  enlarged. 

No.  19.  STRENGTH  OF  BEAMS  UNDER  TRANSVERSE  LOADS. 
By  Prof.  W.  Allan,  author  of  "  Theory  of  Arches."  Second 
edition,  revised. 

No.  20.  BRIDGE  AND  TUNNEL  CENTRES.  By  John  B.  McMaster, 
C.E.  Second  edition. 

No.  21.  SAFETY  VALVES.     By  Richard  H.  Buel,  C.E.     Third  edition. 

No.  22.  HIGH  MASONRY  DAMS.  By  E.  Sherman  Gould,  M.  Am. 
Soc.  C.  E. 

Wo.  23.  THE  FATIGUE  OF  METALS  UNDER  REPEATED  STRAINS. 
With  various  Tables  of  Results  and  Experiments.  From  the 
German  of  Prof.  Ludwig  Spangenburg,  with  a  Preface  by  S.  H. 
Shreve,  A.M. 

No.  24.  A  PRACTICAL  TREATISE  ON  THE  TEETH  OF  WHEELS. 
By  Prof.  S.  W.  Robinson.  2nd  edition,  revised,  with  additions. 

No.  25.  THEORY  AND  CALCULATION  OF  CANTILEVER  BRIDGES. 
By  R.  M.  Wilcox. 

No.  26.  PRACTICAL  TREATISE  ON  THE  PROPERTIES  OF  CON- 

tinuous  Bridges.     By  Charles  Bender,  C.E. 

No.  27.  BOILER    INCRUSTATION    AND    CORROSION.     By    F.    J. 

Rowan.     New  edition.     Revised  and  partly  rewritten  by  F.  E. 
Idell. 

No.  28.  TRANSMISSION  OF  POWER  BY  WIRE  ROPES.  By  Albert 
W.  Stahl,  U.S.N.  Second  edition,  revised. 

No.  29.  STEAM  INJECTORS,  THEIR  THEORY  AND  USE.  Trans- 
lated from  the  French  of  M.  Leon  Pochet. 

No.  30.  MAGNETISM    OF    IRON    VESSELS    AND    TERRESTRIAL 

Magnetism.     By  Prof.  Fairman  Rogers. 


D.  VAN  NOSTRAND  COMPANY'S 

No.  31.  THE    SANITARY    CONDITION   OF   CITY  AND    COUNTRY 

Dwelling-houses.     By  George   E.   Waring,  Jr.     Second   edition, 
revised. 

No.  32.  CABLE-MAKING  FOR  SUSPENSION  BRIDGES.  By  W. 
Hildenbrand,  C.E. 

No.  33.  MECHANICS  OF  VENTILATION.  By  George  W.  Rafter,  C.E. 
Second  edition,  revised. 

No.  34.  FOUNDATIONS.  By  Prof.  Jules  Gaudard,  C.E.  Trans- 
lated from  the  French.  Second  edition. 

No.  35.  THE  ANEROID  BAROMETER:    ITS  CONSTRUCTION  AND 

Use.      Compiled    by    George    W.    Plympton.       Ninth    edition, 
revised  and  enlarged. 

No.  36.  MATTER  AND  MOTION.  By  J.  Clerk  Maxwell,  M.A.  Second 
American  edition. 

No.  37.  GEOGRAPHICAL  SURVEYING:  ITS  USES,  METHODS, 
and  Results.  By  Frank  De  Yeaux  Carpenter,  C.E. 

No.  38.  MAXIMUM  STRESSES  IN  FRAMED  BRIDGES.  By  Prof. 
William  Cain,  A.M.,  C.E.  New  and  revised  edition. 

No.  39.  A  HANDBOOK  OF  THE  ELECTRO-MAGNETIC  TELE- 
graph.  By  A.  E.  Loring.  Fourth  edition,  revised. 

No.  40.  TRANSMISSION  OF  POWER  BY  COMPRESSED  AIR.  By 
Robert  Zahner,  M.E.  New  edition,  in  press. 

No.  41.  STRENGTH  OF  MATERIALS.  By  William  Kent,  C.E., 
Assoc.  Editor  "Engineering  News."  Second  edition. 

No.  42.  THEORY  OF  STEEL-CONCRETE  ARCHES,  AND  OF 
Vaulted  Structures.  By  Prof.  Wm.  Cain.  Third  edition, 
thoroughly  revised. 

No.  43.  WAVE  AND  VORTEX  MOTION.  By  Dr.  Thomas  Craig, 
of  Johns  Hopkins  University. 

No.  44.  TURBINE  WHEELS.  By  Prof.  W.  P.  Trowbridge,  Columbia 
College.  Second  edition.  Revised. 

No.  45.  THERMO-DYNAMICS.  By  Prof.  H.  T.  Eddy,  University 
of  Cincinnati.  New  edition,  in  press. 

No.  46.  ICE-MAKING  MACHINES.  From  the  French  of  M.  Le  Doux. 
Revised  by  Prof.  J.  E.  Denton,  D.  S.  Jacobus,  and  A.  Riesenberger. 
Fifth  edition,  revised. 

No.  47.  LINKAGES:  THE  DIFFERENT  FORMS  AND  USES  OF 
Articulated  Links.  By  J.  D.  C.  De  Roos. 

No.  48.  THEORY  OF  SOLID  AND  BRACED  ELASTIC  ARCHES 
By  William  Cain,  C.E. 

No.  49.  MOTION  OF  A  SOLID  IN  A  FLUID.     By  Thomas  Craig,  Ph.D. 


SCIENTIFIC  PUBLICATIONS. 

No.  50.  DWELLING-HOUSES:      THEIR     SANITARY     CONSTRUC- 

tion  and  Arrangements.     By  Prof.  W.  H.  Corfield. 

No.  51.  THE  TELESCOPE  :  OPTICAL  PRINCIPLES  INVOLVED  IN 
the  Construction  of  Refracting  and  Reflecting  Telescopes,  with 
a  new  chapter  on  the  Evolution  of  the  Modern  Telescope,  and  a 
Bibliography  to  date.  With  diagrams  and  folding  plates.  By 
Thomas  Nolan.  Second  edition,  revised  and  enlarged. 

No.  52.  IMAGINARY    QUANTITIES:     THEIR    GEOMETRICAL    IN- 

terpretation.     Translated  from    the    French    of    M.    Argand  by 
Prof.  A.  S.  Hardy. 

No.  53.  INDUCTION    COILS:     HOW    MADE    AND    HOW    USED. 

Eleventh   American    edition. 

No.  54.  KINEMATICS    OF    MACHINERY.     By    Prof.    Alex.    B.    W. 

Kennedy.     With  an  introduction  by  Prof.  R.  H.  Thurston. 

No.  55.  SEWER  GASES:    THEIR  NATURE  AND  ORIGIN.     By  A. 

de  Varona.     Second  edition,  revised  and  enlarged. 

No.  56.  THE  ACTUAL  LATERAL  PRESSURE  OF  EARTHWORK. 

By  Benj.  Baker,  M.  Inst.,  C.E. 

No.  57.  INCANDESCENT  ELECTRIC  LIGHTING.  A  Practical  De- 
scription of  the  Edison  System.  By  L.  H.  Latimer.  To 
which  is  added  the  Design  and  Operation  of  Incandescent  Sta- 
tions, by  C.  J.  Field;  and  the  Maximum  Efficiency  of  Incandescent 
Lamps,  by  John  W.  Howell. 

No.  58.  VENTILATION  OF  COAL  MINES.  By  W.  Fairley,  M.E., 
and  Geo.  J.  Andre. 

No.  59.  RAILROAD  ECONOMICS;  OR,  NOTES  WITH  COMMENTS. 
By  S.  W.  Robinson,  C.E. 

No.  60.  STRENGTH  OF  WROUGHT-IRON  BRIDGE  MEMBERS. 
By  S.  W.  Robinson,  C.E. 

No.  61.  POTABLE    WATER,    AND    METHODS    OF    DETECTING 

Impurities.     By  M.  N.  Baker.    Second  ed.,  revised  and  enlarged. 

No.  62.  THEORY  OF  THE  GAS-ENGINE.  By  Dougald  Clerk.  Third 
edition.  With  additional  matter.  Edited  by  F.  E.  Idell,  M.E. 

No.  63.  HOUSE-DRAINAGE  AND  SANITARY  PLUMBING.  By  W. 
P.  Gerhard.  Tenth  edition. 

No.  64.  ELECTRO-MAGNETS.     By  A.  N.  Mansfield. 

No.  65.  POCKET  LOGARITHMS  TO  FOUR  PLACES  OF  DECIMALS. 

Including  Logarithms  of  Numbers,  etc. 

No.  66.  DYNAMO-ELECTRIC  MACHINERY.  By  S.  P.  Thompson. 
With  an  Introduction  by  F.  L.  Pope.  Third  edition,  revised. 

No.  67.  HYDRAULIC  TABLES  FOR  THE  CALCULATION  OF  THE 
Discharge  through  Sewers,  Pipes,  and  Conduits.  Based  on 
"Kutter's  Formula."  By  P.  J.  Flynn. 


D.  VAN  NOSTRAND  COMPANY'S 

No.  68.  STEAM-HEATING.  By  Robert  Briggs.  Third  edition,  re- 
vised, with  additions  by  A.  R.  Wolff. 

No.  69.  CHEMICAL    PROBLEMS.     By    Prof.    J.     C.    Foye.     Fourth 

edition,  revised  and  enlarged. 

No.  70.  EXPLOSIVE  MATERIALS.     By  Lieut.  John  P.  Wisser. 

No.  71.  DYNAMIC  ELECTRICITY.  By  John  Hopkinson,  J.  A. 
Shoolbred,  and  R.  E.  Day. 

No.  72.  TOPOGRAPHICAL  SURVEYING.  By  George  J.  Specht 
Prof.  A.  S.  Hardy,  John  B.  McMaster,  and  H.  F.  Walling.  Third 
edition,  revised. 

No.  73.  SYMBOLIC  ALGEBRA;  OR,  THE  ALGEBRA  OF  ALGE- 

braic  Numbers.     By  Prof.  William  Cain. 

N®.  74.  TESTING  MACHINES:  THEIR  HISTORY,  CONSTRUC- 
tion  and  Use.  By  Arthur  V.  Abbott. 

No.  75.  RECENT  PROGRESS  IN  DYNAMO-ELECTRIC  MACHINES. 

Being    a    Supplement    to    " Dynamo-electric    Machinery."      By 
Prof.  Sylvanus  P.  Thompson. 

No.  76.  MODERN  REPRODUCTIVE  GRAPHIC  PROCESSES.  By 
Lieut.  James  S.  Pettit,  U.S.A. 

No.  77.  STADIA  SURVEYING.  The  Theory  of  Stadia  Measure- 
ments. By  Arthur  WTinslow.  Sixth  edition. 

No.  78.  THE  STEAM-ENGINE  INDICATOR  AND  ITS  USE.  By 
W.  B.  Le  Van. 

No.  79.  THE  FIGURE  OF  THE  EARTH.     By  Frank  C.  Roberts,  C.E. 

No.  80.  HEALTHY  FOUNDATIONS  FOR  HOUSES.  By  Glenn 
Brown. 

No.  81.  WATER  METERS:  COMPARATIVE  TESTS  OF  ACCURACY, 

Delivery,   etc.     Distinctive   features  of   the   Worthington,    Ken- 
nedy, Siemens,  and  Hesse  meters.     By  Ross  E.  Browne. 

No.  82.  THE  PRESERVATION  OF  TIMBER  BY  THE  USE  OF  ANTI- 

septics.     By  Samuel  Bagster  Boulton,  C.E. 

No.  83.  MECHANICAL  INTEGRATORS.  By  Prof.  Henry  S.  H. 
Shaw,  C.E. 

No.  84.  FLOW  OF  WATER  IN  OPEN  CHANNELS,  PIPES,  CON- 
duits,  Sewers,  etc.  With  Tables.  By  P.  J.  Flynn,  C.E. 

No.  85.  THE  LUMINIFEROUS  AETHER.     By  Prof.  De  Volson  Wood. 

No.  86.  HANDBOOK   OF   MINERALOGY:     DETERMINATION,    DE- 

scription,  and   Classification     f   Minerals   Found    in   the  United 
States.     By  Prof.  J.  C.  Foye.     Fifth  edition,  revised. 


SCIENTIFIC  PUBLICATIONS. 

No.  87.  TREATISE  ON  THE  THEORY  OF  THE  CONSTRUCTION 

of  Helicoidal  Oblique  Arches.     By  John  L.  Culley,  C.E. 

No.  88.  BEAMS  AND  GIRDERS.  Practical  Formulas  for  their  Resist- 
ance. By  P.  H.  Philbrick. 

No.  89.  MODERN    GUN    COTTON:     ITS    MANUFACTURE,    PROP- 

erties,  and  Analyses.     By  Lieut.  John  P.  Wisser,  UJ3.A. 

No.  90.  ROTARY   MOTION  AS  APPLIED    TO    THE   GYROSCOPE. 

By  Major  J.  G.  Barnard. 

No.  91.  LEVELING:       BAROMETRIC,      TRIGONOMETRIC,      AND 

Spirit.     By  Prof.  I.  O.  Baker.    Second  edition. 

No.  92.  PETROLEUM:  ITS  PRODUCTION  AND  USE.  By  Boverton 
Redwood,  F.I.C.,  F.C.S. 

No.  93.  RECENT  PRACTICE  IN  THE  SANITARY  DRAINAGE  OF 
Buildings.  With  Memoranda  on  the  Cost  of  Plumbing  Work. 
Second  edition,  revised  and  enlarged.  By  William  Paul  Ger- 
hard, C.E. 

No.  94.  THE  TREATMENT  OF  SEWAGE.  By  Dr.  C.  Meymott 
Tidy. 

No.  95.  PLATE-GIRDER  CONSTRUCTION.  By  Isami  Hiroi,  C.E. 
Fourth  edition,  revised. 

No.  96.  ALTERNATE  CURRENT  MACHINERY.  By  Gisbert  Kapp, 
Assoc.  M.  Inst.,  C.E. 

No.  97.  THE  DISPOSAL  OF  HOUSEHOLD  WASTES.  By  W.  Paul 
Gerhard,  Sanitary  Engineer. 

No.  98.  PRACTICAL  DYNAMO-BUILDING  FOR  AMATEURS.     HOW 

to  Wind  for  Any  Output.      By  Frederick  Walker.      Fully  illus- 
trated.    Third  edition. 

No.  99.  TRIPLE-EXPANSION  ENGINES  AND  ENGINE  TRIALS. 
By  Prof.  Osborne  Reynolds.  Edited  with  notes,  etc.,  by  F.  E. 
Well,  M.E. 

No.  100.  HOW  TO  BECpME  AN  ENGINEER;    or.  The  Theoretical 

and  Practical  Training  necessary  in  Fitting  for  the  Duties  of 
the  Civil  Engineer.     By  Prof.  Geo.  W.  Plympton. 

No.  101.  THE  SEXTANT,  and  Other  Reflecting  Mathematical  Instru- 
ments. With  Practical  Hints  for  their  Adjustment  and  Use. 
By  F.  R.  Brainard,  U.  S.  Navy. 

No.  102.  THE  GALVANIC  CIRCUIT  INVESTIGATED  MATHE- 
matically.  By  Dr.  G.  S.  Ohm,  Berlin,  1827.  Translated  by 
William  Francis.  With  Preface  and  Notes  by  the  Editor,  Thomaa 
D.  Lockwood,  M.I.E.E. 


D.  VAN  NOSTRAND  COMPANY'S 

No.  103.  THE  MICROSCOPICAL  EXAMINATION  OF  POTABLE 
Water.  With  Diagrams.  By  Geo.  W.  Rafter.  Second  edition. 

No.  104.  VAN  NOSTRAND'S  TABLE-BOOK  FOR  CIVIL  AND  ME- 

chanical  Engineers.     Compiled  by  Prof.  Geo.  W.  Plympton. 

No.  105.  DETERMINANTS.  An  Introduction  to  the  Study  of,  with 
Examples  and  Applications.  By  Prof.  G.  A.  Miller. 

No.  106.  COMPRESSED  AIR.  Experiments  upon  the  Transmission  of 
Power  by  Compressed  Air  in  Paris.  (Popp's  System.)  By 
Prof.  A.  B.  W.  Kennedy.  The  Transmission  and  Distribution 
of  Power  from  Central  Stations  by  Compressed  Air.  By  Prof. 
W.  C.  Unwin.  Edited  by  F.  E.  Idell.  Third  edition. 

No.  107.  A    GRAPHICAL    METHOD    FOR    SWING    BRIDGES.      A 

Rational  and  Easy  Graphical  Analysis  of  the  Stresses  in  Ordinary 
Swing  Bridges.  With  an  Introduction  on  the  General  Theory 
of  Graphical  Statics,  with  Folding  Plates.  By  Benjamin  F. 
La  Rue. 

No.  1 08.  SLIDE-VALVE  DIAGRAMS.  A  French  Method  for  Con- 
structing Slide-valve  Diagrams.  By  Lloyd  Bankson,  B.S., 
Assistant  Naval  Constructor,  U.  S.  Navy.  8  Folding  Plates. 

No.  109.  THE  MEASUREMENT  OF  ELECTRIC  CURRENTS.  Elec- 
trical Measuring  Instruments.  By  James  Swinburne.  Meters 
for  Electrical  Energy.  By  C.  H.  Wordingham.  Edited,  with 
Preface,  by  T.  Commerford  Martin.  With  Folding  Plate  and 
Numerous  Illustrations. 

No.  no.  TRANSITION  CURVES.  A  Field-book  for  Engineers,  Con- 
taining Rules  and  Tables  for  Laying  out  Transition  Curves.  By 
Walter  G.  Fox,  C.E. 

No.  in.  GAS-LIGHTING  AND  GAS-FITTING.  Specifications  and 
Rules  for  Gas-piping.  Notes  on  the  Advantages  of  Gas  for 
Cooking  and  Heating,  and  Useful  Hints  to  Gas  Consumers.  Third 
edition.  By  Wm.  Paul  Gerhard,  C.E. 

No.  112.  A  PRIMER  ON  THE  CALCULUS,  By  E.  Sherman  Gould, 
M.  Am.  Soc.  C.  E.  Third  edition,  revised  and  enlarged. 

No.  113.  PHYSICAL  PROBLEMS  and  Their  Solution.  By  A.  Bour- 
gougnon,  formerly  Assistant  at  Bellevue  Hospital.  Second  ed. 

No.  114.  MANUAL  OF  THE  SLIDE  RULE.  By  F.  A.  Halsey,  of 
the  "American  Machinist."  Third  edition,  corrected. 

No.  115.  TRAVERSE  TABLE.  Showing  the  Difference  of  Latitude 
and  Departure  for  Distances  Between  1  and  100  and  for  Angles  to 
Quarter  Degrees  Between  1  Degree  and  90  Degrees.  (Reprinted 
from  Seribner's  Pocket  Table  Book.) 


SCIENTIFIC  PUBLICATIONS. 

No.  116.  WORM  AND  SPIRAL  GEARING.  Reprinted  from  "Ameri- 
can Machinist."  By  F.  A.  Halsey.  Second  revised  and  enlarged 
edition. 

No.  117.  PRACTICAL  HYDROSTATICS,  AND  HYDROSTATIC  FOR- 
mulas.  With  Numerous  Illustrative  Figures  and  Numerical 
Examples.  By  E.  Sherman  Gould. 

No.  118.  TREATMENT  OF  SEPTIC  SEWAGE,  with  Diagrams  and 
Figures.  By  Geo.  W.  Rafter. 

No.  119.  LAY-OUT  OF  CORLISS  VALVE  GEARS.  With  Folding 
Plates  and  Diagrams.  By  Sanford  A.  Moss,  M.S  ,  Ph.D  Re- 
printed from  "The  American  Machinist,"  with  revisions  and 
additions.  Second  edition. 

No.  120.  ART  OF  GENERATING  GEAR  TEETH.  By  Howard  A. 
Coombs.  With  Figures,  Diagrams  and  Folding  Plates.  Re- 
printed from  the  "American  Machinist." 

No.  121.  ELEMENTS  OF  GAS  ENGINE  DESIGN.  Reprint  of  a  Set 
of  Notes  accompanying  a  Course  of  Lectures  delivered  at  Cornell 
University  in  1902.  By  Sanford  A.  Moss.  Illustrated. 

No.  122.  SHAFT  GOVERNORS.  By  W.  Trinks  and  C.  Housum.  Il- 
lustrated. 

No.  123.  FURNACE  DRAFT;  ITS  PRODUCTION  BY  MECHANICAL 
Methods.  A  Handy  Reference  Book,  with  figures  and  tables.  By 
William  Wallace  Christie.  Illustrated. 


YC  33037. 


I  7711 


